Title pretty much - for a while now videos won't play in any format in Firefox. They work fine in Chrome and other browsers. Any ideas on what might be causing this?

I've had this problem too. The only solution that's worked for me is to click the download button, and it plays the video in a separate tab

same

If this info is useful for debugging, I've had this issue on firefox mobile (I use android), but it's fine on the PC.

same issue here, just installed firefox for the first time on this pc this week too.

I use Firefox myself and the solution that worked for me was going through my extensions to see which one caused it. For me it was "Audio Equalizer" and when I removed it, everything worked fine

Then stop using Firefox

That's very helpful.

It's really that simple