URL: https://www.twitch.tv

Browser / Version: Firefox 140.0
Operating System: Ubuntu
Tested Another Browser: Yes Chrome

Problem type: Video or audio doesn't play
Description: There is no video
Steps to Reproduce:
After updating to 140 and even 140a1, I get this error any time I try to play a live Twitch stream: "This video is either unavailable or not supported in this browser. (Error #4000)"
Reinstalling on my laptop (same OS, same version of Firefox) made no change.

View the screenshot

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