+    def _extract_playlist(self, playlist_id):
+        url = self._TEMPLATE_URL % playlist_id
+        page = self._download_webpage(url, playlist_id)
+
+        for match in re.findall(r'<div class="yt-alert-message">([^<]+)</div>', page):
+            match = match.strip()
+            # Check if the playlist exists or is private
+            if re.match(r'[^<]*(The|This) playlist (does not exist|is private)[^<]*', match):
+                raise ExtractorError(
+                    'The playlist doesn\'t exist or is private, use --username or '
+                    '--netrc to access it.',
+                    expected=True)
+            elif re.match(r'[^<]*Invalid parameters[^<]*', match):
+                raise ExtractorError(
+                    'Invalid parameters. Maybe URL is incorrect.',
+                    expected=True)
+            elif re.match(r'[^<]*Choose your language[^<]*', match):
+                continue
+            else:
+                self.report_warning('Youtube gives an alert message: ' + match)
+
+        # Extract the video ids from the playlist pages
+        def _entries():
+            more_widget_html = content_html = page
+            for page_num in itertools.count(1):
+                matches = re.finditer(self._VIDEO_RE, content_html)
+                # We remove the duplicates and the link with index 0
+                # (it's not the first video of the playlist)
+                new_ids = orderedSet(m.group('id') for m in matches if m.group('index') != '0')
+                for vid_id in new_ids:
+                    yield self.url_result(vid_id, 'Youtube', video_id=vid_id)
+
+                mobj = re.search(r'data-uix-load-more-href="/?(?P<more>[^"]+)"', more_widget_html)
+                if not mobj:
+                    break
+
+                more = self._download_json(
+                    'https://youtube.com/%s' % mobj.group('more'), playlist_id,
+                    'Downloading page #%s' % page_num,
+                    transform_source=uppercase_escape)
+                content_html = more['content_html']
+                if not content_html.strip():
+                    # Some webpages show a "Load more" button but they don't
+                    # have more videos
+                    break
+                more_widget_html = more['load_more_widget_html']
+
+        playlist_title = self._html_search_regex(
+            r'(?s)<h1 class="pl-header-title[^"]*">\s*(.*?)\s*</h1>',
+            page, 'title')
+
+        return self.playlist_result(_entries(), playlist_id, playlist_title)
+