Also, I wanted to say that the video was a YouTube video, and when I try to modify the speed of the video using the inbuilt YouTube playback speed controls on the video itself, that doesn't work either! So what's going on?

Hi Clara, it's odd that the custom YouTube controls don't work, either.

If you hold down the Shift key while right-clicking the video, hopefully you will get Firefox's own video context menu. Does that one work?

Hi jscher2000, Thank you very much for replying. I just tried that and it doesn't work at all either. Unfortunately.

What else can I do to fix this so that I can increase video speeds again, and so that the extension I had been using will work again? And why would modifying the video speed suddenly stop working when it had been perfectly fine up to now?

I'm not sure what happened. It's still working for me after today's update. Have you tried doing a regular shut down and restart of Windows in case this is a misunderstanding between Firefox and the various system media components it uses?

Also, since this problem started, I went into the browser settings and clicked "use recommended performance settings", and then restarted the browser, but that didn't help at all.

Just to check, I tried using Vivaldi and Edge browsers and increasing the speed worked fine on both of them. I guess the restart is the next step, although I'm a little reluctant and wary to try that since my computer has had problems after restarts in the past...

Before I try the restart, is there anything else at all that I can do that might help with this, other than just using another browser?

Hi Clara, I'm not aware of any setting that prevents us from changing video speeds. It seems more likely to be a transient glitch.

But why not wait and see what other comments you get.

Thank you very much for your time and attention to this problem, I really appreciate it.

I really hope that this problem can be resolved and I'm eager to see what other comments there might be.

It is annoying to have to switch to another browser...

Did you check for issues (interactions) between Video Speed Control and other extensions you have installed ?

Start Firefox in Troubleshoot Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or userChrome.css is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
• do NOT click the "Refresh Firefox" button on the Troubleshoot Mode start window

• https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

Hi cor-el,

Thank you very much for your help, your suggestions worked and solved the problem.

Hardware acceleration or UserChrome weren't the problem (I didn't even know what UserChrome was before, had to Google it), nor was the theme the problem either. It turns out it was this volume control extension that was causing the problem, and not letting the speed of videos be modified; disabling and removing this extension fixed the problem: https://addons.mozilla.org/en-US/firefox/addon/600-sound-volume/. It's too bad since this extension was very useful, now something else will have to be found to replace it.

Although I did find something interesting when looking for a replacement: It seems that when having volume control extensions in Firefox, they prevent the video speed from being changed at all from the basic 1x speed. Somebody else was complaining about the exact same problem in the reviews section of another volume control extension (see attached image).

It is still puzzling though, that everything was fine previously even with this volume control extension in my browser, and then suddenly out of nowhere this problem started happening and wasn't fixed until I removed the volume control extension.

I hope another extension or other solution can be found that will allow the volume in videos to be increased while at the same time being able to increase the video speed. If anyone knows of any such thing, I am eager to hear about it.

Thank you very much for your help, I really appreciate it.