diff --git a/.github/workflows/quick-test.yml b/.github/workflows/quick-test.yml
index 1a32bbfe31..8a7b24033f 100644
--- a/.github/workflows/quick-test.yml
+++ b/.github/workflows/quick-test.yml
@@ -38,3 +38,5 @@ jobs:
       run: ruff check --output-format github .
     - name: Run autopep8
       run: autopep8 --diff .
+    - name: Check file mode
+      run: git ls-files --format="%(objectmode) %(path)" yt_dlp/ | ( ! grep -v "^100644" )
diff --git a/README.md b/README.md
index 0cc2cd7b2c..d7d3ce3495 100644
--- a/README.md
+++ b/README.md
@@ -1799,9 +1799,6 @@ The following extractors use this feature:
 #### vikichannel
 * `video_types`: Types of videos to download - one or more of `episodes`, `movies`, `clips`, `trailers`
 
-#### niconico
-* `segment_duration`: Segment duration in milliseconds for HLS-DMC formats. Use it at your own risk since this feature **may result in your account termination.**
-
 #### youtubewebarchive
 * `check_all`: Try to check more at the cost of more requests. One or more of `thumbnails`, `captures`
 
diff --git a/yt_dlp/downloader/__init__.py b/yt_dlp/downloader/__init__.py
index 1b12bd4bed..9c34bd289a 100644
--- a/yt_dlp/downloader/__init__.py
+++ b/yt_dlp/downloader/__init__.py
@@ -30,7 +30,7 @@ from .hls import HlsFD
 from .http import HttpFD
 from .ism import IsmFD
 from .mhtml import MhtmlFD
-from .niconico import NiconicoDmcFD, NiconicoLiveFD
+from .niconico import NiconicoLiveFD
 from .rtmp import RtmpFD
 from .rtsp import RtspFD
 from .websocket import WebSocketFragmentFD
@@ -50,7 +50,6 @@ PROTOCOL_MAP = {
     'http_dash_segments_generator': DashSegmentsFD,
     'ism': IsmFD,
     'mhtml': MhtmlFD,
-    'niconico_dmc': NiconicoDmcFD,
     'niconico_live': NiconicoLiveFD,
     'fc2_live': FC2LiveFD,
     'websocket_frag': WebSocketFragmentFD,
@@ -67,7 +66,6 @@ def shorten_protocol_name(proto, simplify=False):
         'rtmp_ffmpeg': 'rtmpF',
         'http_dash_segments': 'dash',
         'http_dash_segments_generator': 'dashG',
-        'niconico_dmc': 'dmc',
         'websocket_frag': 'WSfrag',
     }
     if simplify:
diff --git a/yt_dlp/downloader/niconico.py b/yt_dlp/downloader/niconico.py
index 310144e7d2..33cf15df88 100644
--- a/yt_dlp/downloader/niconico.py
+++ b/yt_dlp/downloader/niconico.py
@@ -2,60 +2,12 @@ import json
 import threading
 import time
 
-from . import get_suitable_downloader
 from .common import FileDownloader
 from .external import FFmpegFD
 from ..networking import Request
 from ..utils import DownloadError, str_or_none, try_get
 
 
-class NiconicoDmcFD(FileDownloader):
-    """ Downloading niconico douga from DMC with heartbeat """
-
-    def real_download(self, filename, info_dict):
-        from ..extractor.niconico import NiconicoIE
-
-        self.to_screen(f'[{self.FD_NAME}] Downloading from DMC')
-        ie = NiconicoIE(self.ydl)
-        info_dict, heartbeat_info_dict = ie._get_heartbeat_info(info_dict)
-
-        fd = get_suitable_downloader(info_dict, params=self.params)(self.ydl, self.params)
-
-        success = download_complete = False
-        timer = [None]
-        heartbeat_lock = threading.Lock()
-        heartbeat_url = heartbeat_info_dict['url']
-        heartbeat_data = heartbeat_info_dict['data'].encode()
-        heartbeat_interval = heartbeat_info_dict.get('interval', 30)
-
-        request = Request(heartbeat_url, heartbeat_data)
-
-        def heartbeat():
-            try:
-                self.ydl.urlopen(request).read()
-            except Exception:
-                self.to_screen(f'[{self.FD_NAME}] Heartbeat failed')
-
-            with heartbeat_lock:
-                if not download_complete:
-                    timer[0] = threading.Timer(heartbeat_interval, heartbeat)
-                    timer[0].start()
-
-        heartbeat_info_dict['ping']()
-        self.to_screen('[%s] Heartbeat with %d second interval ...' % (self.FD_NAME, heartbeat_interval))
-        try:
-            heartbeat()
-            if type(fd).__name__ == 'HlsFD':
-                info_dict.update(ie._extract_m3u8_formats(info_dict['url'], info_dict['id'])[0])
-            success = fd.real_download(filename, info_dict)
-        finally:
-            if heartbeat_lock:
-                with heartbeat_lock:
-                    timer[0].cancel()
-                    download_complete = True
-        return success
-
-
 class NiconicoLiveFD(FileDownloader):
     """ Downloads niconico live without being stopped """
 
diff --git a/yt_dlp/extractor/_extractors.py b/yt_dlp/extractor/_extractors.py
index 047af92820..bb1c3db16e 100644
--- a/yt_dlp/extractor/_extractors.py
+++ b/yt_dlp/extractor/_extractors.py
@@ -1042,6 +1042,7 @@ from .limelight import (
     LimelightMediaIE,
 )
 from .linkedin import (
+    LinkedInEventsIE,
     LinkedInIE,
     LinkedInLearningCourseIE,
     LinkedInLearningIE,
diff --git a/yt_dlp/extractor/bpb.py b/yt_dlp/extractor/bpb.py
index d7bf58b366..a2a9082527 100644
--- a/yt_dlp/extractor/bpb.py
+++ b/yt_dlp/extractor/bpb.py
@@ -7,6 +7,7 @@ from ..utils import (
     join_nonempty,
     js_to_json,
     mimetype2ext,
+    parse_resolution,
     unified_strdate,
     url_or_none,
     urljoin,
@@ -110,24 +111,23 @@ class BpbIE(InfoExtractor):
 
         return attributes
 
-    @staticmethod
-    def _process_source(source):
+    def _process_source(self, source):
         url = url_or_none(source['src'])
         if not url:
             return None
 
         source_type = source.get('type', '')
         extension = mimetype2ext(source_type)
-        is_video = source_type.startswith('video')
-        note = url.rpartition('.')[0].rpartition('_')[2] if is_video else None
+        note = self._search_regex(r'[_-]([a-z]+)\.[\da-z]+(?:$|\?)', url, 'note', default=None)
 
         return {
             'url': url,
             'ext': extension,
-            'vcodec': None if is_video else 'none',
+            'vcodec': None if source_type.startswith('video') else 'none',
             'quality': 10 if note == 'high' else 0,
             'format_note': note,
             'format_id': join_nonempty(extension, note),
+            **parse_resolution(source.get('label')),
         }
 
     def _real_extract(self, url):
diff --git a/yt_dlp/extractor/dacast.py b/yt_dlp/extractor/dacast.py
index 537352e5f7..ffc7ca8246 100644
--- a/yt_dlp/extractor/dacast.py
+++ b/yt_dlp/extractor/dacast.py
@@ -9,6 +9,7 @@ from ..utils import (
     ExtractorError,
     classproperty,
     float_or_none,
+    parse_qs,
     traverse_obj,
     url_or_none,
 )
@@ -91,11 +92,15 @@ class DacastVODIE(DacastBaseIE):
         # Rotates every so often, but hardcode a fallback in case of JS change/breakage before rotation
         return self._search_regex(
             r'\bUSP_SIGNING_SECRET\s*=\s*(["\'])(?P<secret>(?:(?!\1).)+)', player_js,
-            'usp signing secret', group='secret', fatal=False) or 'odnInCGqhvtyRTtIiddxtuRtawYYICZP'
+            'usp signing secret', group='secret', fatal=False) or 'hGDtqMKYVeFdofrAfFmBcrsakaZELajI'
 
     def _real_extract(self, url):
         user_id, video_id = self._match_valid_url(url).group('user_id', 'id')
-        query = {'contentId': f'{user_id}-vod-{video_id}', 'provider': 'universe'}
+        query = {
+            'contentId': f'{user_id}-vod-{video_id}',
+            'provider': 'universe',
+            **traverse_obj(url, ({parse_qs}, 'uss_token', {'signedKey': -1})),
+        }
         info = self._download_json(self._API_INFO_URL, video_id, query=query, fatal=False)
         access = self._download_json(
             'https://playback.dacast.com/content/access', video_id,
diff --git a/yt_dlp/extractor/linkedin.py b/yt_dlp/extractor/linkedin.py
index d25f0fe6a0..2974f4026f 100644
--- a/yt_dlp/extractor/linkedin.py
+++ b/yt_dlp/extractor/linkedin.py
@@ -1,4 +1,5 @@
 import itertools
+import json
 import re
 
 from .common import InfoExtractor
@@ -9,12 +10,12 @@ from ..utils import (
     int_or_none,
     mimetype2ext,
     srt_subtitles_timecode,
-    traverse_obj,
     try_get,
     url_or_none,
     urlencode_postdata,
     urljoin,
 )
+from ..utils.traversal import find_elements, require, traverse_obj
 
 
 class LinkedInBaseIE(InfoExtractor):
@@ -277,3 +278,110 @@ class LinkedInLearningCourseIE(LinkedInLearningBaseIE):
             entries, course_slug,
             course_data.get('title'),
             course_data.get('description'))
+
+
+class LinkedInEventsIE(LinkedInBaseIE):
+    IE_NAME = 'linkedin:events'
+    _VALID_URL = r'https?://(?:www\.)?linkedin\.com/events/(?P<id>[\w-]+)'
+    _TESTS = [{
+        'url': 'https://www.linkedin.com/events/7084656651378536448/comments/',
+        'info_dict': {
+            'id': '7084656651378536448',
+            'ext': 'mp4',
+            'title': '#37 Aprende a hacer una entrevista en inglés para tu próximo trabajo remoto',
+            'description': '¡Agarra para anotar que se viene tremendo evento!',
+            'duration': 1765,
+            'timestamp': 1689113772,
+            'upload_date': '20230711',
+            'release_timestamp': 1689174012,
+            'release_date': '20230712',
+            'live_status': 'was_live',
+        },
+    }, {
+        'url': 'https://www.linkedin.com/events/27-02energyfreedombyenergyclub7295762520814874625/comments/',
+        'info_dict': {
+            'id': '27-02energyfreedombyenergyclub7295762520814874625',
+            'ext': 'mp4',
+            'title': '27.02 Energy Freedom by Energy Club',
+            'description': 'md5:1292e6f31df998914c293787a02c3b91',
+            'duration': 6420,
+            'timestamp': 1739445333,
+            'upload_date': '20250213',
+            'release_timestamp': 1740657620,
+            'release_date': '20250227',
+            'live_status': 'was_live',
+        },
+    }]
+
+    def _real_initialize(self):
+        if not self._get_cookies('https://www.linkedin.com/').get('li_at'):
+            self.raise_login_required()
+
+    def _real_extract(self, url):
+        event_id = self._match_id(url)
+        webpage = self._download_webpage(url, event_id)
+
+        base_data = traverse_obj(webpage, (
+            {find_elements(tag='code', attr='style', value='display: none')}, ..., {json.loads}, 'included', ...))
+        meta_data = traverse_obj(base_data, (
+            lambda _, v: v['$type'] == 'com.linkedin.voyager.dash.events.ProfessionalEvent', any)) or {}
+
+        live_status = {
+            'PAST': 'was_live',
+            'ONGOING': 'is_live',
+            'FUTURE': 'is_upcoming',
+        }.get(meta_data.get('lifecycleState'))
+
+        if live_status == 'is_upcoming':
+            player_data = {}
+            if event_time := traverse_obj(meta_data, ('displayEventTime', {str})):
+                message = f'This live event is scheduled for {event_time}'
+            else:
+                message = 'This live event has not yet started'
+            self.raise_no_formats(message, expected=True, video_id=event_id)
+        else:
+            # TODO: Add support for audio-only live events
+            player_data = traverse_obj(base_data, (
+                lambda _, v: v['$type'] == 'com.linkedin.videocontent.VideoPlayMetadata',
+                any, {require('video player data')}))
+
+        formats, subtitles = [], {}
+        for prog_fmts in traverse_obj(player_data, ('progressiveStreams', ..., {dict})):
+            for fmt_url in traverse_obj(prog_fmts, ('streamingLocations', ..., 'url', {url_or_none})):
+                formats.append({
+                    'url': fmt_url,
+                    **traverse_obj(prog_fmts, {
+                        'width': ('width', {int_or_none}),
+                        'height': ('height', {int_or_none}),
+                        'tbr': ('bitRate', {int_or_none(scale=1000)}),
+                        'filesize': ('size', {int_or_none}),
+                        'ext': ('mediaType', {mimetype2ext}),
+                    }),
+                })
+
+        for m3u8_url in traverse_obj(player_data, (
+            'adaptiveStreams', lambda _, v: v['protocol'] == 'HLS', 'masterPlaylists', ..., 'url', {url_or_none},
+        )):
+            fmts, subs = self._extract_m3u8_formats_and_subtitles(
+                m3u8_url, event_id, 'mp4', m3u8_id='hls', fatal=False)
+            formats.extend(fmts)
+            self._merge_subtitles(subs, target=subtitles)
+
+        return {
+            'id': event_id,
+            'formats': formats,
+            'subtitles': subtitles,
+            'live_status': live_status,
+            **traverse_obj(meta_data, {
+                'title': ('name', {str}),
+                'description': ('description', 'text', {str}),
+                'timestamp': ('createdAt', {int_or_none(scale=1000)}),
+                # timeRange.start is available when the stream is_upcoming
+                'release_timestamp': ('timeRange', 'start', {int_or_none(scale=1000)}),
+            }),
+            **traverse_obj(player_data, {
+                'duration': ('duration', {int_or_none(scale=1000)}),
+                # liveStreamCreatedAt is only available when the stream is_live or was_live
+                'release_timestamp': ('liveStreamCreatedAt', {int_or_none(scale=1000)}),
+            }),
+        }
diff --git a/yt_dlp/extractor/mlb.py b/yt_dlp/extractor/mlb.py
index f7726e5b11..562b93fc78 100644
--- a/yt_dlp/extractor/mlb.py
+++ b/yt_dlp/extractor/mlb.py
@@ -365,13 +365,15 @@ mutation initPlaybackSession(
                 'All videos are only available to registered users', method='password')
 
     def _set_device_id(self, username):
-        if not self._device_id:
-            self._device_id = self.cache.load(
-                self._NETRC_MACHINE, 'device_ids', default={}).get(username)
+        if self._device_id:
+            return
+        device_id_cache = self.cache.load(self._NETRC_MACHINE, 'device_ids', default={})
+        self._device_id = device_id_cache.get(username)
         if self._device_id:
             return
         self._device_id = str(uuid.uuid4())
-        self.cache.store(self._NETRC_MACHINE, 'device_ids', {username: self._device_id})
+        device_id_cache[username] = self._device_id
+        self.cache.store(self._NETRC_MACHINE, 'device_ids', device_id_cache)
 
     def _perform_login(self, username, password):
         try:
diff --git a/yt_dlp/extractor/niconico.py b/yt_dlp/extractor/niconico.py
index 5e66aebeba..52ba6c417c 100644
--- a/yt_dlp/extractor/niconico.py
+++ b/yt_dlp/extractor/niconico.py
@@ -16,7 +16,6 @@ from ..utils import (
     determine_ext,
     float_or_none,
     int_or_none,
-    join_nonempty,
     parse_duration,
     parse_iso8601,
     parse_qs,
@@ -24,7 +23,6 @@ from ..utils import (
     qualities,
     remove_start,
     str_or_none,
-    traverse_obj,
     try_get,
     unescapeHTML,
     unified_timestamp,
@@ -34,13 +32,70 @@ from ..utils import (
     urlencode_postdata,
     urljoin,
 )
+from ..utils.traversal import find_element, traverse_obj
 
 
-class NiconicoIE(InfoExtractor):
+class NiconicoBaseIE(InfoExtractor):
+    _GEO_BYPASS = False
+    _GEO_COUNTRIES = ['JP']
+    _LOGIN_BASE = 'https://account.nicovideo.jp'
+    _NETRC_MACHINE = 'niconico'
+
+    @property
+    def is_logged_in(self):
+        return bool(self._get_cookies('https://www.nicovideo.jp').get('user_session'))
+
+    def _raise_login_error(self, message, expected=True):
+        raise ExtractorError(f'Unable to login: {message}', expected=expected)
+
+    def _perform_login(self, username, password):
+        if self.is_logged_in:
+            return
+
+        self._request_webpage(
+            f'{self._LOGIN_BASE}/login', None, 'Requesting session cookies')
+        webpage = self._download_webpage(
+            f'{self._LOGIN_BASE}/login/redirector', None,
+            'Logging in', 'Unable to log in', headers={
+                'Content-Type': 'application/x-www-form-urlencoded',
+                'Referer': f'{self._LOGIN_BASE}/login',
+            }, data=urlencode_postdata({
+                'mail_tel': username,
+                'password': password,
+            }))
+
+        if self.is_logged_in:
+            return
+        elif err_msg := traverse_obj(webpage, (
+            {find_element(cls='notice error')}, {find_element(cls='notice__text')}, {clean_html},
+        )):
+            self._raise_login_error(err_msg or 'Invalid username or password')
+        elif 'oneTimePw' in webpage:
+            post_url = self._search_regex(
+                r'<form[^>]+action=(["\'])(?P<url>.+?)\1', webpage, 'post url', group='url')
+            mfa, urlh = self._download_webpage_handle(
+                urljoin(self._LOGIN_BASE, post_url), None,
+                'Performing MFA', 'Unable to complete MFA', headers={
+                    'Content-Type': 'application/x-www-form-urlencoded',
+                }, data=urlencode_postdata({
+                    'otp': self._get_tfa_info('6 digit number shown on app'),
+                }))
+            if self.is_logged_in:
+                return
+            elif 'error-code' in parse_qs(urlh.url):
+                err_msg = traverse_obj(mfa, ({find_element(cls='pageMainMsg')}, {clean_html}))
+                self._raise_login_error(err_msg or 'MFA session expired')
+            elif 'formError' in mfa:
+                err_msg = traverse_obj(mfa, (
+                    {find_element(cls='formError')}, {find_element(tag='div')}, {clean_html}))
+                self._raise_login_error(err_msg or 'MFA challenge failed')
+
+        self._raise_login_error('Unexpected login error', expected=False)
+
+
+class NiconicoIE(NiconicoBaseIE):
     IE_NAME = 'niconico'
     IE_DESC = 'ニコニコ動画'
-    _GEO_COUNTRIES = ['JP']
-    _GEO_BYPASS = False
 
     _TESTS = [{
         'url': 'http://www.nicovideo.jp/watch/sm22312215',
@@ -180,229 +235,6 @@ class NiconicoIE(InfoExtractor):
     }]
 
     _VALID_URL = r'https?://(?:(?:www\.|secure\.|sp\.)?nicovideo\.jp/watch|nico\.ms)/(?P<id>(?:[a-z]{2})?[0-9]+)'
-    _NETRC_MACHINE = 'niconico'
-    _API_HEADERS = {
-        'X-Frontend-ID': '6',
-        'X-Frontend-Version': '0',
-        'X-Niconico-Language': 'en-us',
-        'Referer': 'https://www.nicovideo.jp/',
-        'Origin': 'https://www.nicovideo.jp',
-    }
-
-    def _perform_login(self, username, password):
-        login_ok = True
-        login_form_strs = {
-            'mail_tel': username,
-            'password': password,
-        }
-        self._request_webpage(
-            'https://account.nicovideo.jp/login', None,
-            note='Acquiring Login session')
-        page = self._download_webpage(
-            'https://account.nicovideo.jp/login/redirector?show_button_twitter=1&site=niconico&show_button_facebook=1', None,
-            note='Logging in', errnote='Unable to log in',
-            data=urlencode_postdata(login_form_strs),
-            headers={
-                'Referer': 'https://account.nicovideo.jp/login',
-                'Content-Type': 'application/x-www-form-urlencoded',
-            })
-        if 'oneTimePw' in page:
-            post_url = self._search_regex(
-                r'<form[^>]+action=(["\'])(?P<url>.+?)\1', page, 'post url', group='url')
-            page = self._download_webpage(
-                urljoin('https://account.nicovideo.jp', post_url), None,
-                note='Performing MFA', errnote='Unable to complete MFA',
-                data=urlencode_postdata({
-                    'otp': self._get_tfa_info('6 digits code'),
-                }), headers={
-                    'Content-Type': 'application/x-www-form-urlencoded',
-                })
-            if 'oneTimePw' in page or 'formError' in page:
-                err_msg = self._html_search_regex(
-                    r'formError["\']+>(.*?)</div>', page, 'form_error',
-                    default='There\'s an error but the message can\'t be parsed.',
-                    flags=re.DOTALL)
-                self.report_warning(f'Unable to log in: MFA challenge failed, "{err_msg}"')
-                return False
-        login_ok = 'class="notice error"' not in page
-        if not login_ok:
-            self.report_warning('Unable to log in: bad username or password')
-        return login_ok
-
-    def _get_heartbeat_info(self, info_dict):
-        video_id, video_src_id, audio_src_id = info_dict['url'].split(':')[1].split('/')
-        dmc_protocol = info_dict['expected_protocol']
-
-        api_data = (
-            info_dict.get('_api_data')
-            or self._parse_json(
-                self._html_search_regex(
-                    'data-api-data="([^"]+)"',
-                    self._download_webpage('https://www.nicovideo.jp/watch/' + video_id, video_id),
-                    'API data', default='{}'),
-                video_id))
-
-        session_api_data = try_get(api_data, lambda x: x['media']['delivery']['movie']['session'])
-        session_api_endpoint = try_get(session_api_data, lambda x: x['urls'][0])
-
-        def ping():
-            tracking_id = traverse_obj(api_data, ('media', 'delivery', 'trackingId'))
-            if tracking_id:
-                tracking_url = update_url_query('https://nvapi.nicovideo.jp/v1/2ab0cbaa/watch', {'t': tracking_id})
-                watch_request_response = self._download_json(
-                    tracking_url, video_id,
-                    note='Acquiring permission for downloading video', fatal=False,
-                    headers=self._API_HEADERS)
-                if traverse_obj(watch_request_response, ('meta', 'status')) != 200:
-                    self.report_warning('Failed to acquire permission for playing video. Video download may fail.')
-
-        yesno = lambda x: 'yes' if x else 'no'
-
-        if dmc_protocol == 'http':
-            protocol = 'http'
-            protocol_parameters = {
-                'http_output_download_parameters': {
-                    'use_ssl': yesno(session_api_data['urls'][0]['isSsl']),
-                    'use_well_known_port': yesno(session_api_data['urls'][0]['isWellKnownPort']),
-                },
-            }
-        elif dmc_protocol == 'hls':
-            protocol = 'm3u8'
-            segment_duration = try_get(self._configuration_arg('segment_duration'), lambda x: int(x[0])) or 6000
-            parsed_token = self._parse_json(session_api_data['token'], video_id)
-            encryption = traverse_obj(api_data, ('media', 'delivery', 'encryption'))
-            protocol_parameters = {
-                'hls_parameters': {
-                    'segment_duration': segment_duration,
-                    'transfer_preset': '',
-                    'use_ssl': yesno(session_api_data['urls'][0]['isSsl']),
-                    'use_well_known_port': yesno(session_api_data['urls'][0]['isWellKnownPort']),
-                },
-            }
-            if 'hls_encryption' in parsed_token and encryption:
-                protocol_parameters['hls_parameters']['encryption'] = {
-                    parsed_token['hls_encryption']: {
-                        'encrypted_key': encryption['encryptedKey'],
-                        'key_uri': encryption['keyUri'],
-                    },
-                }
-            else:
-                protocol = 'm3u8_native'
-        else:
-            raise ExtractorError(f'Unsupported DMC protocol: {dmc_protocol}')
-
-        session_response = self._download_json(
-            session_api_endpoint['url'], video_id,
-            query={'_format': 'json'},
-            headers={'Content-Type': 'application/json'},
-            note='Downloading JSON metadata for {}'.format(info_dict['format_id']),
-            data=json.dumps({
-                'session': {
-                    'client_info': {
-                        'player_id': session_api_data.get('playerId'),
-                    },
-                    'content_auth': {
-                        'auth_type': try_get(session_api_data, lambda x: x['authTypes'][session_api_data['protocols'][0]]),
-                        'content_key_timeout': session_api_data.get('contentKeyTimeout'),
-                        'service_id': 'nicovideo',
-                        'service_user_id': session_api_data.get('serviceUserId'),
-                    },
-                    'content_id': session_api_data.get('contentId'),
-                    'content_src_id_sets': [{
-                        'content_src_ids': [{
-                            'src_id_to_mux': {
-                                'audio_src_ids': [audio_src_id],
-                                'video_src_ids': [video_src_id],
-                            },
-                        }],
-                    }],
-                    'content_type': 'movie',
-                    'content_uri': '',
-                    'keep_method': {
-                        'heartbeat': {
-                            'lifetime': session_api_data.get('heartbeatLifetime'),
-                        },
-                    },
-                    'priority': session_api_data['priority'],
-                    'protocol': {
-                        'name': 'http',
-                        'parameters': {
-                            'http_parameters': {
-                                'parameters': protocol_parameters,
-                            },
-                        },
-                    },
-                    'recipe_id': session_api_data.get('recipeId'),
-                    'session_operation_auth': {
-                        'session_operation_auth_by_signature': {
-                            'signature': session_api_data.get('signature'),
-                            'token': session_api_data.get('token'),
-                        },
-                    },
-                    'timing_constraint': 'unlimited',
-                },
-            }).encode())
-
-        info_dict['url'] = session_response['data']['session']['content_uri']
-        info_dict['protocol'] = protocol
-
-        # get heartbeat info
-        heartbeat_info_dict = {
-            'url': session_api_endpoint['url'] + '/' + session_response['data']['session']['id'] + '?_format=json&_method=PUT',
-            'data': json.dumps(session_response['data']),
-            # interval, convert milliseconds to seconds, then halve to make a buffer.
-            'interval': float_or_none(session_api_data.get('heartbeatLifetime'), scale=3000),
-            'ping': ping,
-        }
-
-        return info_dict, heartbeat_info_dict
-
-    def _extract_format_for_quality(self, video_id, audio_quality, video_quality, dmc_protocol):
-
-        if not audio_quality.get('isAvailable') or not video_quality.get('isAvailable'):
-            return None
-
-        format_id = '-'.join(
-            [remove_start(s['id'], 'archive_') for s in (video_quality, audio_quality)] + [dmc_protocol])
-
-        vid_qual_label = traverse_obj(video_quality, ('metadata', 'label'))
-
-        return {
-            'url': 'niconico_dmc:{}/{}/{}'.format(video_id, video_quality['id'], audio_quality['id']),
-            'format_id': format_id,
-            'format_note': join_nonempty('DMC', vid_qual_label, dmc_protocol.upper(), delim=' '),
-            'ext': 'mp4',  # Session API are used in HTML5, which always serves mp4
-            'acodec': 'aac',
-            'vcodec': 'h264',
-            **traverse_obj(audio_quality, ('metadata', {
-                'abr': ('bitrate', {float_or_none(scale=1000)}),
-                'asr': ('samplingRate', {int_or_none}),
-            })),
-            **traverse_obj(video_quality, ('metadata', {
-                'vbr': ('bitrate', {float_or_none(scale=1000)}),
-                'height': ('resolution', 'height', {int_or_none}),
-                'width': ('resolution', 'width', {int_or_none}),
-            })),
-            'quality': -2 if 'low' in video_quality['id'] else None,
-            'protocol': 'niconico_dmc',
-            'expected_protocol': dmc_protocol,  # XXX: This is not a documented field
-            'http_headers': {
-                'Origin': 'https://www.nicovideo.jp',
-                'Referer': 'https://www.nicovideo.jp/watch/' + video_id,
-            },
-        }
-
-    def _yield_dmc_formats(self, api_data, video_id):
-        dmc_data = traverse_obj(api_data, ('media', 'delivery', 'movie'))
-        audios = traverse_obj(dmc_data, ('audios', ..., {dict}))
-        videos = traverse_obj(dmc_data, ('videos', ..., {dict}))
-        protocols = traverse_obj(dmc_data, ('session', 'protocols', ..., {str}))
-        if not all((audios, videos, protocols)):
-            return
-
-        for audio_quality, video_quality, protocol in itertools.product(audios, videos, protocols):
-            if fmt := self._extract_format_for_quality(video_id, audio_quality, video_quality, protocol):
-                yield fmt
 
     def _yield_dms_formats(self, api_data, video_id):
         fmt_filter = lambda _, v: v['isAvailable'] and v['id']
@@ -485,8 +317,8 @@ class NiconicoIE(InfoExtractor):
             'needs_premium': ('isPremium', {bool}),
             'needs_subscription': ('isAdmission', {bool}),
         })) or {'needs_auth': True}))
-        formats = [*self._yield_dmc_formats(api_data, video_id),
-                   *self._yield_dms_formats(api_data, video_id)]
+
+        formats = list(self._yield_dms_formats(api_data, video_id))
         if not formats:
             fail_msg = clean_html(self._html_search_regex(
                 r'<p[^>]+\bclass="fail-message"[^>]*>(?P<msg>.+?)</p>',
@@ -921,7 +753,7 @@ class NiconicoUserIE(InfoExtractor):
         return self.playlist_result(self._entries(list_id), list_id)
 
 
-class NiconicoLiveIE(InfoExtractor):
+class NiconicoLiveIE(NiconicoBaseIE):
     IE_NAME = 'niconico:live'
     IE_DESC = 'ニコニコ生放送'
     _VALID_URL = r'https?://(?:sp\.)?live2?\.nicovideo\.jp/(?:watch|gate)/(?P<id>lv\d+)'
diff --git a/yt_dlp/extractor/rai.py b/yt_dlp/extractor/rai.py
index efb47affc9..c489dc7312 100644
--- a/yt_dlp/extractor/rai.py
+++ b/yt_dlp/extractor/rai.py
@@ -321,6 +321,27 @@ class RaiPlayIE(RaiBaseIE):
             'timestamp': 1348495020,
             'upload_date': '20120924',
         },
+    }, {
+        # checking program_info gives false positive for DRM
+        'url': 'https://www.raiplay.it/video/2022/10/Ad-ogni-costo---Un-giorno-in-Pretura---Puntata-del-15102022-1dfd1295-ea38-4bac-b51e-f87e2881693b.html',
+        'md5': '572c6f711b7c5f2d670ba419b4ae3b08',
+        'info_dict': {
+            'id': '1dfd1295-ea38-4bac-b51e-f87e2881693b',
+            'ext': 'mp4',
+            'title': 'Ad ogni costo - Un giorno in Pretura - Puntata del 15/10/2022',
+            'alt_title': 'St 2022/23 - Un giorno in pretura - Ad ogni costo',
+            'description': 'md5:4046d97b2687f74f06a8b8270ba5599f',
+            'uploader': 'Rai 3',
+            'duration': 3773.0,
+            'thumbnail': 'https://www.raiplay.it/dl/img/2022/10/12/1665586539957_2048x2048.png',
+            'creators': ['Rai 3'],
+            'series': 'Un giorno in pretura',
+            'season': '2022/23',
+            'episode': 'Ad ogni costo',
+            'timestamp': 1665507240,
+            'upload_date': '20221011',
+            'release_year': 2025,
+        },
     }, {
         'url': 'http://www.raiplay.it/video/2016/11/gazebotraindesi-efebe701-969c-4593-92f3-285f0d1ce750.html?',
         'only_matching': True,
@@ -340,9 +361,8 @@ class RaiPlayIE(RaiBaseIE):
         media = self._download_json(
             f'{base}.json', video_id, 'Downloading video JSON')
 
-        if not self.get_param('allow_unplayable_formats'):
-            if traverse_obj(media, (('program_info', None), 'rights_management', 'rights', 'drm')):
-                self.report_drm(video_id)
+        if traverse_obj(media, ('rights_management', 'rights', 'drm')):
+            self.report_drm(video_id)
 
         video = media['video']
         relinker_info = self._extract_relinker_info(video['content_url'], video_id)
diff --git a/yt_dlp/extractor/reddit.py b/yt_dlp/extractor/reddit.py
index a7a6a75dc4..be4c32e135 100644
--- a/yt_dlp/extractor/reddit.py
+++ b/yt_dlp/extractor/reddit.py
@@ -388,7 +388,8 @@ class RedditIE(InfoExtractor):
                     })
             if entries:
                 return self.playlist_result(entries, video_id, **info)
-            raise ExtractorError('No media found', expected=True)
+            self.raise_no_formats('No media found', expected=True, video_id=video_id)
+            return {**info, 'id': video_id}
 
         # Check if media is hosted on reddit:
         reddit_video = traverse_obj(data, (
diff --git a/yt_dlp/extractor/tv2dk.py b/yt_dlp/extractor/tv2dk.py
index 9cd7606b0a..bad120f7b4 100644
--- a/yt_dlp/extractor/tv2dk.py
+++ b/yt_dlp/extractor/tv2dk.py
@@ -2,12 +2,13 @@ import json
 import re
 
 from .common import InfoExtractor
+from .jwplatform import JWPlatformIE
 from ..utils import (
     determine_ext,
-    extract_attributes,
     js_to_json,
     url_or_none,
 )
+from ..utils.traversal import find_element, traverse_obj
 
 
 class TV2DKIE(InfoExtractor):
@@ -21,35 +22,46 @@ class TV2DKIE(InfoExtractor):
                             tv2fyn|
                             tv2east|
                             tv2lorry|
-                            tv2nord
+                            tv2nord|
+                            tv2kosmopol
                         )\.dk/
-                        (:[^/]+/)*
+                        (?:[^/?#]+/)*
                         (?P<id>[^/?\#&]+)
                     '''
     _TESTS = [{
         'url': 'https://www.tvsyd.dk/nyheder/28-10-2019/1930/1930-28-okt-2019?autoplay=1#player',
         'info_dict': {
-            'id': '0_52jmwa0p',
+            'id': 'sPp5z21q',
             'ext': 'mp4',
             'title': '19:30 - 28. okt. 2019',
-            'timestamp': 1572290248,
+            'description': '',
+            'thumbnail': 'https://cdn.jwplayer.com/v2/media/sPp5z21q/poster.jpg?width=720',
+            'timestamp': 1572287400,
             'upload_date': '20191028',
-            'uploader_id': 'tvsyd',
-            'duration': 1347,
-            'view_count': int,
         },
-        'add_ie': ['Kaltura'],
     }, {
         'url': 'https://www.tv2lorry.dk/gadekamp/gadekamp-6-hoejhuse-i-koebenhavn',
         'info_dict': {
-            'id': '1_7iwll9n0',
+            'id': 'oD9cyq0m',
             'ext': 'mp4',
-            'upload_date': '20211027',
             'title': 'Gadekamp #6 - Højhuse i København',
-            'uploader_id': 'tv2lorry',
-            'timestamp': 1635345229,
+            'description': '',
+            'thumbnail': 'https://cdn.jwplayer.com/v2/media/oD9cyq0m/poster.jpg?width=720',
+            'timestamp': 1635348600,
+            'upload_date': '20211027',
         },
-        'add_ie': ['Kaltura'],
+    }, {
+        'url': 'https://www.tvsyd.dk/haderslev/x-factor-brodre-fulde-af-selvtillid-er-igen-hjemme-hos-mor-vores-diagnoser-har-vaeret-en-fordel',
+        'info_dict': {
+            'id': 'x-factor-brodre-fulde-af-selvtillid-er-igen-hjemme-hos-mor-vores-diagnoser-har-vaeret-en-fordel',
+        },
+        'playlist_count': 2,
+    }, {
+        'url': 'https://www.tv2ostjylland.dk/aarhus/dom-kan-fa-alvorlige-konsekvenser',
+        'info_dict': {
+            'id': 'dom-kan-fa-alvorlige-konsekvenser',
+        },
+        'playlist_count': 3,
     }, {
         'url': 'https://www.tv2ostjylland.dk/artikel/minister-gaar-ind-i-sag-om-diabetes-teknologi',
         'only_matching': True,
@@ -71,40 +83,22 @@ class TV2DKIE(InfoExtractor):
     }, {
         'url': 'https://www.tv2nord.dk/artikel/dybt-uacceptabelt',
         'only_matching': True,
+    }, {
+        'url': 'https://www.tv2kosmopol.dk/metropolen/chaufforer-beordres-til-at-kore-videre-i-ulovlige-busser-med-rode-advarselslamper',
+        'only_matching': True,
     }]
 
     def _real_extract(self, url):
         video_id = self._match_id(url)
-
         webpage = self._download_webpage(url, video_id)
+        search_space = traverse_obj(webpage, {find_element(tag='article')}) or webpage
 
-        entries = []
+        player_ids = traverse_obj(
+            re.findall(r'x-data="(?:video_player|simple_player)\(({[^"]+})', search_space),
+            (..., {js_to_json}, {json.loads}, ('jwpMediaId', 'videoId'), {str}))
 
-        def add_entry(partner_id, kaltura_id):
-            entries.append(self.url_result(
-                f'kaltura:{partner_id}:{kaltura_id}', 'Kaltura',
-                video_id=kaltura_id))
-
-        for video_el in re.findall(r'(?s)<[^>]+\bdata-entryid\s*=[^>]*>', webpage):
-            video = extract_attributes(video_el)
-            kaltura_id = video.get('data-entryid')
-            if not kaltura_id:
-                continue
-            partner_id = video.get('data-partnerid')
-            if not partner_id:
-                continue
-            add_entry(partner_id, kaltura_id)
-        if not entries:
-            kaltura_id = self._search_regex(
-                (r'entry_id\s*:\s*["\']([0-9a-z_]+)',
-                 r'\\u002FentryId\\u002F(\w+)\\u002F'), webpage, 'kaltura id')
-            partner_id = self._search_regex(
-                (r'\\u002Fp\\u002F(\d+)\\u002F', r'/p/(\d+)/'), webpage,
-                'partner id')
-            add_entry(partner_id, kaltura_id)
-        if len(entries) == 1:
-            return entries[0]
-        return self.playlist_result(entries)
+        return self.playlist_from_matches(
+            player_ids, video_id, getter=lambda x: f'jwplatform:{x}', ie=JWPlatformIE)
 
 
 class TV2DKBornholmPlayIE(InfoExtractor):
diff --git a/yt_dlp/extractor/twitch.py b/yt_dlp/extractor/twitch.py
index a36de3c017..4f4c59627f 100644
--- a/yt_dlp/extractor/twitch.py
+++ b/yt_dlp/extractor/twitch.py
@@ -1225,8 +1225,8 @@ class TwitchClipsIE(TwitchBaseIE):
                 'channel_id': ('broadcaster', 'id', {str}),
                 'channel_follower_count': ('broadcaster', 'followers', 'totalCount', {int_or_none}),
                 'channel_is_verified': ('broadcaster', 'isPartner', {bool}),
-                'uploader': ('broadcaster', 'displayName', {str}),
-                'uploader_id': ('broadcaster', 'id', {str}),
+                'uploader': ('curator', 'displayName', {str}),
+                'uploader_id': ('curator', 'id', {str}),
                 'categories': ('game', 'displayName', {str}, filter, all, filter),
             }),
         }
diff --git a/yt_dlp/extractor/twitter.py b/yt_dlp/extractor/twitter.py
index b76cfae1db..5eee3e7263 100644
--- a/yt_dlp/extractor/twitter.py
+++ b/yt_dlp/extractor/twitter.py
@@ -1221,20 +1221,10 @@ class TwitterIE(TwitterBaseIE):
     }]
 
     _MEDIA_ID_RE = re.compile(r'_video/(\d+)/')
-
-    @property
-    def _GRAPHQL_ENDPOINT(self):
-        if self.is_logged_in:
-            return 'zZXycP0V6H7m-2r0mOnFcA/TweetDetail'
-        return '2ICDjqPd81tulZcYrtpTuQ/TweetResultByRestId'
+    _GRAPHQL_ENDPOINT = '2ICDjqPd81tulZcYrtpTuQ/TweetResultByRestId'
 
     def _graphql_to_legacy(self, data, twid):
-        result = traverse_obj(data, (
-            'threaded_conversation_with_injections_v2', 'instructions', 0, 'entries',
-            lambda _, v: v['entryId'] == f'tweet-{twid}', 'content', 'itemContent',
-            'tweet_results', 'result', ('tweet', None), {dict},
-        ), default={}, get_all=False) if self.is_logged_in else traverse_obj(
-            data, ('tweetResult', 'result', {dict}), default={})
+        result = traverse_obj(data, ('tweetResult', 'result', {dict})) or {}
 
         typename = result.get('__typename')
         if typename not in ('Tweet', 'TweetWithVisibilityResults', 'TweetTombstone', 'TweetUnavailable', None):
@@ -1278,37 +1268,6 @@ class TwitterIE(TwitterBaseIE):
 
     def _build_graphql_query(self, media_id):
         return {
-            'variables': {
-                'focalTweetId': media_id,
-                'includePromotedContent': True,
-                'with_rux_injections': False,
-                'withBirdwatchNotes': True,
-                'withCommunity': True,
-                'withDownvotePerspective': False,
-                'withQuickPromoteEligibilityTweetFields': True,
-                'withReactionsMetadata': False,
-                'withReactionsPerspective': False,
-                'withSuperFollowsTweetFields': True,
-                'withSuperFollowsUserFields': True,
-                'withV2Timeline': True,
-                'withVoice': True,
-            },
-            'features': {
-                'graphql_is_translatable_rweb_tweet_is_translatable_enabled': False,
-                'interactive_text_enabled': True,
-                'responsive_web_edit_tweet_api_enabled': True,
-                'responsive_web_enhance_cards_enabled': True,
-                'responsive_web_graphql_timeline_navigation_enabled': False,
-                'responsive_web_text_conversations_enabled': False,
-                'responsive_web_uc_gql_enabled': True,
-                'standardized_nudges_misinfo': True,
-                'tweet_with_visibility_results_prefer_gql_limited_actions_policy_enabled': False,
-                'tweetypie_unmention_optimization_enabled': True,
-                'unified_cards_ad_metadata_container_dynamic_card_content_query_enabled': True,
-                'verified_phone_label_enabled': False,
-                'vibe_api_enabled': True,
-            },
-        } if self.is_logged_in else {
             'variables': {
                 'tweetId': media_id,
                 'withCommunity': False,
@@ -1717,21 +1676,22 @@ class TwitterSpacesIE(TwitterBaseIE):
     _VALID_URL = TwitterBaseIE._BASE_REGEX + r'i/spaces/(?P<id>[0-9a-zA-Z]{13})'
 
     _TESTS = [{
-        'url': 'https://twitter.com/i/spaces/1RDxlgyvNXzJL',
+        'url': 'https://twitter.com/i/spaces/1OwxWwQOPlNxQ',
         'info_dict': {
-            'id': '1RDxlgyvNXzJL',
+            'id': '1OwxWwQOPlNxQ',
             'ext': 'm4a',
-            'title': 'King Carlo e la mossa Kansas City per fare il Grande Centro',
-            'description': 'Twitter Space participated by annarita digiorgio, Signor Ernesto, Raffaello Colosimo, Simone M. Sepe',
-            'uploader': r're:Lucio Di Gaetano.*?',
-            'uploader_id': 'luciodigaetano',
+            'title': 'Everybody in: @mtbarra & @elonmusk discuss the future of EV charging',
+            'description': 'Twitter Space participated by Elon Musk',
             'live_status': 'was_live',
-            'timestamp': 1659877956,
-            'upload_date': '20220807',
-            'release_timestamp': 1659904215,
-            'release_date': '20220807',
+            'release_date': '20230608',
+            'release_timestamp': 1686256230,
+            'thumbnail': r're:https?://pbs\.twimg\.com/profile_images/.+',
+            'timestamp': 1686254250,
+            'upload_date': '20230608',
+            'uploader': 'Mary Barra',
+            'uploader_id': 'mtbarra',
         },
-        'skip': 'No longer available',
+        'params': {'skip_download': 'm3u8'},
     }, {
         # post_live/TimedOut but downloadable
         'url': 'https://twitter.com/i/spaces/1vAxRAVQWONJl',
@@ -1743,9 +1703,10 @@ class TwitterSpacesIE(TwitterBaseIE):
             'uploader': 'Google Cloud',
             'uploader_id': 'googlecloud',
             'live_status': 'post_live',
+            'thumbnail': r're:https?://pbs\.twimg\.com/profile_images/.+',
             'timestamp': 1681409554,
             'upload_date': '20230413',
-            'release_timestamp': 1681839000,
+            'release_timestamp': 1681839082,
             'release_date': '20230418',
             'protocol': 'm3u8',  # ffmpeg is forced
             'container': 'm4a_dash',  # audio-only format fixup is applied
@@ -1762,6 +1723,9 @@ class TwitterSpacesIE(TwitterBaseIE):
             'uploader': '息根とめる',
             'uploader_id': 'tomeru_ikinone',
             'live_status': 'was_live',
+            'release_date': '20230601',
+            'release_timestamp': 1685617200,
+            'thumbnail': r're:https?://pbs\.twimg\.com/profile_images/.+',
             'timestamp': 1685617198,
             'upload_date': '20230601',
             'protocol': 'm3u8',  # ffmpeg is forced
@@ -1779,9 +1743,10 @@ class TwitterSpacesIE(TwitterBaseIE):
             'uploader': 'Candace Owens',
             'uploader_id': 'RealCandaceO',
             'live_status': 'was_live',
+            'thumbnail': r're:https?://pbs\.twimg\.com/profile_images/.+',
             'timestamp': 1723931351,
             'upload_date': '20240817',
-            'release_timestamp': 1723932000,
+            'release_timestamp': 1723932056,
             'release_date': '20240817',
             'protocol': 'm3u8_native',  # not ffmpeg, detected as video space
         },
@@ -1861,18 +1826,21 @@ class TwitterSpacesIE(TwitterBaseIE):
 
         return {
             'id': space_id,
-            'title': metadata.get('title'),
             'description': f'Twitter Space participated by {participants}',
-            'uploader': traverse_obj(
-                metadata, ('creator_results', 'result', 'legacy', 'name')),
-            'uploader_id': traverse_obj(
-                metadata, ('creator_results', 'result', 'legacy', 'screen_name')),
-            'live_status': live_status,
-            'release_timestamp': try_call(
-                lambda: int_or_none(metadata['scheduled_start'], scale=1000)),
-            'timestamp': int_or_none(metadata.get('created_at'), scale=1000),
             'formats': formats,
             'http_headers': headers,
+            'live_status': live_status,
+            **traverse_obj(metadata, {
+                'title': ('title', {str}),
+                # started_at is None when stream is_upcoming so fallback to scheduled_start for --wait-for-video
+                'release_timestamp': (('started_at', 'scheduled_start'), {int_or_none(scale=1000)}, any),
+                'timestamp': ('created_at', {int_or_none(scale=1000)}),
+            }),
+            **traverse_obj(metadata, ('creator_results', 'result', 'legacy', {
+                'uploader': ('name', {str}),
+                'uploader_id': ('screen_name', {str_or_none}),
+                'thumbnail': ('profile_image_url_https', {lambda x: x.replace('_normal', '_400x400')}, {url_or_none}),
+            })),
         }
 
 
diff --git a/yt_dlp/extractor/vk.py b/yt_dlp/extractor/vk.py
old mode 100755
new mode 100644
diff --git a/yt_dlp/extractor/youtube/_base.py b/yt_dlp/extractor/youtube/_base.py
index 8ca7d898e9..4194e1c217 100644
--- a/yt_dlp/extractor/youtube/_base.py
+++ b/yt_dlp/extractor/youtube/_base.py
@@ -417,6 +417,8 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
 
     _NETRC_MACHINE = 'youtube'
 
+    _COOKIE_HOWTO_WIKI_URL = 'https://github.com/yt-dlp/yt-dlp/wiki/Extractors#exporting-youtube-cookies'
+
     def ucid_or_none(self, ucid):
         return self._search_regex(rf'^({self._YT_CHANNEL_UCID_RE})$', ucid, 'UC-id', default=None)
 
@@ -451,17 +453,15 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
         return preferred_lang
 
     def _initialize_consent(self):
-        cookies = self._get_cookies('https://www.youtube.com/')
-        if cookies.get('__Secure-3PSID'):
+        if self._has_auth_cookies:
             return
-        socs = cookies.get('SOCS')
+        socs = self._youtube_cookies.get('SOCS')
         if socs and not socs.value.startswith('CAA'):  # not consented
             return
         self._set_cookie('.youtube.com', 'SOCS', 'CAI', secure=True)  # accept all (required for mixes)
 
     def _initialize_pref(self):
-        cookies = self._get_cookies('https://www.youtube.com/')
-        pref_cookie = cookies.get('PREF')
+        pref_cookie = self._youtube_cookies.get('PREF')
         pref = {}
         if pref_cookie:
             try:
@@ -472,8 +472,9 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
         self._set_cookie('.youtube.com', name='PREF', value=urllib.parse.urlencode(pref))
 
     def _initialize_cookie_auth(self):
-        yt_sapisid, yt_1psapisid, yt_3psapisid = self._get_sid_cookies()
-        if yt_sapisid or yt_1psapisid or yt_3psapisid:
+        self._passed_auth_cookies = False
+        if self._has_auth_cookies:
+            self._passed_auth_cookies = True
             self.write_debug('Found YouTube account cookies')
 
     def _real_initialize(self):
@@ -492,8 +493,7 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
 
     @property
     def _youtube_login_hint(self):
-        return (f'{self._login_hint(method="cookies")}. Also see  '
-                'https://github.com/yt-dlp/yt-dlp/wiki/Extractors#exporting-youtube-cookies  '
+        return (f'{self._login_hint(method="cookies")}. Also see  {self._COOKIE_HOWTO_WIKI_URL}  '
                 'for tips on effectively exporting YouTube cookies')
 
     def _check_login_required(self):
@@ -553,12 +553,16 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
 
         return f'{scheme} {"_".join(parts)}'
 
+    @property
+    def _youtube_cookies(self):
+        return self._get_cookies('https://www.youtube.com')
+
     def _get_sid_cookies(self):
         """
         Get SAPISID, 1PSAPISID, 3PSAPISID cookie values
         @returns sapisid, 1psapisid, 3psapisid
         """
-        yt_cookies = self._get_cookies('https://www.youtube.com')
+        yt_cookies = self._youtube_cookies
         yt_sapisid = try_call(lambda: yt_cookies['SAPISID'].value)
         yt_3papisid = try_call(lambda: yt_cookies['__Secure-3PAPISID'].value)
         yt_1papisid = try_call(lambda: yt_cookies['__Secure-1PAPISID'].value)
@@ -595,6 +599,31 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
 
         return ' '.join(authorizations)
 
+    @property
+    def is_authenticated(self):
+        return self._has_auth_cookies
+
+    @property
+    def _has_auth_cookies(self):
+        yt_sapisid, yt_1psapisid, yt_3psapisid = self._get_sid_cookies()
+        # YouTube doesn't appear to clear 3PSAPISID when rotating cookies (as of 2025-04-26)
+        # But LOGIN_INFO is cleared and should exist if logged in
+        has_login_info = 'LOGIN_INFO' in self._youtube_cookies
+        return bool(has_login_info and (yt_sapisid or yt_1psapisid or yt_3psapisid))
+
+    def _request_webpage(self, *args, **kwargs):
+        response = super()._request_webpage(*args, **kwargs)
+
+        # Check that we are still logged-in and cookies have not rotated after every request
+        if getattr(self, '_passed_auth_cookies', None) and not self._has_auth_cookies:
+            self.report_warning(
+                'The provided YouTube account cookies are no longer valid. '
+                'They have likely been rotated in the browser as a security measure. '
+                f'For tips on how to effectively export YouTube cookies, refer to  {self._COOKIE_HOWTO_WIKI_URL} .',
+                only_once=False)
+
+        return response
+
     def _call_api(self, ep, query, video_id, fatal=True, headers=None,
                   note='Downloading API JSON', errnote='Unable to download API page',
                   context=None, api_key=None, api_hostname=None, default_client='web'):
@@ -695,10 +724,6 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
             args, [('VISITOR_DATA', ('INNERTUBE_CONTEXT', 'client', 'visitorData'), ('responseContext', 'visitorData'))],
             expected_type=str)
 
-    @functools.cached_property
-    def is_authenticated(self):
-        return bool(self._get_sid_authorization_header())
-
     def extract_ytcfg(self, video_id, webpage):
         if not webpage:
             return {}
diff --git a/yt_dlp/extractor/youtube/_video.py b/yt_dlp/extractor/youtube/_video.py
index bcfe8b1520..48ca5dc8bd 100644
--- a/yt_dlp/extractor/youtube/_video.py
+++ b/yt_dlp/extractor/youtube/_video.py
@@ -1982,7 +1982,9 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
     def _player_js_cache_key(self, player_url):
         player_id = self._extract_player_info(player_url)
         player_path = remove_start(urllib.parse.urlparse(player_url).path, f'/s/player/{player_id}/')
-        variant = self._INVERSE_PLAYER_JS_VARIANT_MAP.get(player_path)
+        variant = self._INVERSE_PLAYER_JS_VARIANT_MAP.get(player_path) or next((
+            v for k, v in self._INVERSE_PLAYER_JS_VARIANT_MAP.items()
+            if re.fullmatch(re.escape(k).replace('en_US', r'[a-zA-Z0-9_]+'), player_path)), None)
         if not variant:
             self.write_debug(
                 f'Unable to determine player JS variant\n'
@@ -3648,6 +3650,13 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
                     reason = f'{remove_end(reason.strip(), ".")}. {self._youtube_login_hint}'
                 elif get_first(playability_statuses, ('errorScreen', 'playerCaptchaViewModel', {dict})):
                     reason += '. YouTube is requiring a captcha challenge before playback'
+                elif "This content isn't available, try again later" in reason:
+                    reason = (
+                        f'{remove_end(reason.strip(), ".")}. {"Your account" if self.is_authenticated else "The current session"} '
+                        f'has been rate-limited by YouTube for up to an hour. It is recommended to use `-t sleep` to add a delay '
+                        f'between video requests to avoid exceeding the rate limit. For more information, refer to  '
+                        f'https://github.com/yt-dlp/yt-dlp/wiki/Extractors#this-content-isnt-available-try-again-later'
+                    )
                 self.raise_no_formats(reason, expected=True)
 
         keywords = get_first(video_details, 'keywords', expected_type=list) or []