I recently got a new computer, and in trying to get all my old accounts and what not synced up, I noticed that Twitter videos weren't playing for me and giving me a generic "The video could not be played", which was odd and annoying, but not the end of the world. I then went over to Twitch and got the "Your browser encountered an error while decoding the video. (Error #3000)". Meanwhile, Youtube works perfectly fine.

I tried clearing cache/cookies, tried on incognito mode in case it was an issue with one of my extensions, all to no avail - when I swapped over to Edge just to check if it was a computer issue versus a Firefox issue, both sites functioned in Edge just fine. Is there anything else I can try troubleshooting in Firefox to see what's causing this short of trying to uninstall/reinstall again?