Hello Nicolay! Welcome to Sumo!

That Twitch video problem on Firefox is super annoying, especially since audio works and it's fine in other browsers. This sounds like a Firefox-specific glitch on your Windows 7 system. Here are two main things to try:

* Hardware Acceleration:
  * Go to Firefox Settings (those three lines, then "Settings").
  * Find "Performance" and uncheck "Use recommended performance settings."
  * Then, uncheck "Use hardware acceleration when available."
  * Restart Firefox and check Twitch.
* Clean Firefox Profile: Even after reinstalling, old profile data can stick around and cause issues.
  * Type about:profiles in Firefox's address bar and hit Enter.
  * Click "Create a New Profile..." and follow the steps to make a brand-new one.
  * Launch Firefox with this new profile. See if Twitch works there.

Heads up, Windows 7 is quite old, and newer browser features and websites might run into compatibility issues with it. If the above doesn't work, it could be that the OS itself is causing the problem.

Robby

Hardware acceleration or profile stuff that rarely gets touched or changed. What changed is the NEW thing that JUST NOW updated from 11.23.0 to 11.23.1. When the question is about a thing that was working and then somebody else changed that thing so that it is now NOT working (and I want my thing to be working again), then it's not oldness vs. newer features or compatibility issues or the OS. Sometimes it's a new, temporary web issue or other external problem with a service. When watching Twitch most of the day yesterday on my ancient MacOS 10.14 system it worked from video to video without any problems both live and re-broadcasts. After the update, the exact same problem with the background "question mark" GIF covering up the video portion in the window. There are awkward workarounds like using the pop-out controls on preview videos to view the video in another window. But so far the best workaround is to just go to Microsoft Edge which works just fine. It's exhausting to spend fruitless hours troubleshooting technical problems I didn't create and don't understand and aren't my fault. The standard template "did you disable all your extensions? did you flush out all your cookies? did you clear your cache? did you try it on a new profile? did you reset your old profile?" frequently is not therapeutic or even diagnostic. That stuff is for surgically-exact, step-by-step technical fix and not as a smart-bomb general-purpose fix-all.

Thanks for your help. I tried your tips, but the problem has not been resolved.

I will add my message: the problem appeared while watching streams. I watched the stream, everything was fine. Then I just moved to another Twitch channel and this problem immediately appeared there. I haven't changed anything in Firefox, I haven't even restarted it.

Now I think: Twitch updated something on his servers and when I switched to another channel - I connected to the server with the update installed. I think we can only wait for the Firefox developers to add compatibility with the new Twitch features, or use a different browser.

Found an answer there from the reddit user "Sea_Stop":

Solution found on reddit

They modified the CSS to use a has() selector. It doesn't work on older browser versions and causes the width of the player to be 0 instead of 100%.

https://caniuse.com/css-has

This site shows if your browser supports it. Slightly older versions of Chrome and Firefox allow you to change the flags to make it work.

The solution from following reply from the user "CalligrapherNo9724":

for firefox users: about:config, layout.css.has-selector.enabled, set to true as a minus-audio slider is gone, gotta use shift+arrow up/down to change sound now

I almost submitted the post, I have the same issue (Windows 8.1) since May 20th, and even did a screen recording: youtube

Yesterday couldn't find any solutions, but it's just didn't showed up in search engines yet.

I don't understand it but it worked once I restarted Firefox. I did not have to delete cookies.

Hello Nicolay Yakimov,

It should be fixed now with default settings, as Twitch has reverted their change that triggered the issue.