hi, could you go to the firefox menu ≡ > help ? > troubleshooting information, copy the contents of that page and paste them here into a reply on the forum (or if it's too long through a site like https://pastebin.mozilla.org/ and provide the link here)?

this might give us a clue what is going on. thank you!

https://pastebin.mozilla.org/9076588 Here's the link

thank you, nothing looks suspicious there - does it help when you refresh firefox? Refresh Firefox - reset add-ons and settings

Thanks Philipp, but it doesn't change anything. I tried all that before I started the post. And I just tried it again...no luck. I have restarted the computer (3 times) and that hasn't helped either. I ran into this some time back, maybe a year ago? I ended up uninstalling Firefox, restarting the computer and then reinstalling Firefox. It worked back then but hasn't worked this time. It's just odd that this started this morning after Firefox did the update.

David459 said

I have no add ons. Videos just have the circle in the middle like it's always trying to load. Just happened this morning after a Firefox update. It works fine in safe mode or in Windows Edge.

What videos and site? I tried yutubbers and have no issue and any sites with video have no issue running on FF58x64.

Hi WestEnd, Facebook, YouTube, Yahoo anything that runs a video. It is really a puzzle to me.

It was working fine last night. Started it this morning and Firefox updated right before launch and it has not worked since. No new anti-virus or any new apps on the machine. I've had it for years, originally with Windows 7 when it was new.

what does youtube.com/html5 say about supported browser features?

If you encounter any problems, right-click on the player and choose "report playback issue", or let us know on the user support forums. Your feedback will help us continue to improve the player. What does this browser support?

   HTMLVideoElement
   H.264
   WebM VP8

   Media Source Extensions
   MSE & H.264
   MSE & WebM VP9

The HTML5 player is currently used when possible. Supported Browsers

Many browsers support both the video element in HTML5 and either the H.264 video codec or the WebM format. These include:

   Google Chrome
   Microsoft Edge
   Firefox *
   Opera
   Apple Safari

• H.264 playback depends on hardware and operating system support.

But it's not just YouTube, it's every video I click on. I did send YT a screen shot and explained as best I could.

I finally got it to work. I went into the menu, options, general and under performance...unchecked use recommended settings and then unchecked use hardware acceleration when available. Shut down Firefox and opened it again and it plays videos just like before. Thanks for all the help.