Hello! Thank you for taking the time to read my issue report and request for assistance. My system MacBook Pro v 9,2 (late 2012) MAC OS 10.12.6 (Sierra) FF v 115.14.0esr (64-bit) DSL with 250m/bit connection Until the day before yesterday the Youtube pages were running and performing normally. Since yesterday YT pages take several minutes to load. I cleared the FF browser cache, deleted cookies, updated the browser, shutdown the computer, restarted the computer, but the hang problem persists.  I searched the internet for reports of server side issues at YT, but found nothing relevant. I reported the issue in detail to YT, but have not heard back - I'm also not sure the help request to YT even made it out of my computer as the help request form did not provide the normal "Request Sent" confirmation. Back on FF and attempting again to load YT pages: after about a minute FF reports that the YT page is slowing down the browser and requests that the page be "stopped". This is especially true of the "Watch Later" page which seems about ten times slower than the already VERY slow YT page loads in general. Eventually, the Watch Later page loads but is EXTREMELY lethargic, taking several minutes to load a selection.  After a YT page loads and a choice is made the selected video presents at 360p.  Changing to 720p or 1080p only locks the playback.  The 360p playback hangs on a frame and audio runs on alone.  Clicking the playback stop button takes several seconds up to several minutes to process to stop the playback request. Checking other browsers on my machine: Chrome and Opera load and run YT pages normally, including the Watch Later page, with fast loads and instant HD playback. I'm including a screen shot of the FF browser on the YT WL page after it has fully loaded. It took several minutes for the page to load as seen in the screen shot, but on selecting a video it hangs until FF generates a stop request as seen at the top of the browser window in the attached image. There have been no changes to the computer or installations of new software of any kind except for updating FF which obviously did not in and of itself solve the issue. The issue presented the same before and after the FF version update. Thank you in advance for any guidance or suggestions on solving the issue. Kind regards, A