You will have to take this to the developer of this theme and file an issue.

WARNING: modifications made through a userChrome.css or userContent.css file can stop working as Firefox evolves in new releases, and can break Firefox or cause strange behavior.

Update the theme to the latest version 2.2 with fixes for Firefox 117 and see if it still happen with all your extensions disabled.

Update the theme to the latest version 2.2 with fixes for Firefox 117 and see if it still happen with all your extensions disabled.

I'm already using 2.2 version, just tried yesterday.

Does it still happen with all your extensions disabled?

Does it still happen with all your extensions disabled?

Actuall I didn't tried with disabling extensions, I removed that CSS theme and using default theme right now but it seems browser still not working properly. For example, when I minimize the window and open it again after a few minutes, the browser becomes unresponsive and freezes for 6-7 seconds. These issues happened after 117 update and I don't know what should I do. Also I tried to remove all components of Firefox (including reg records) and reinstall, it didn't work either. Tried resetting too.

I'm using uBlock Origin, Simple Translate, Search by Image and IDM extensions. I'm also using Dynamic star theme.

Does it still happen in a new profile? An easy way to test a new profile is to install Developer Edition and see if it happens there or refresh your existing profile.

Does it still happen in a new profile? An easy way to test a new profile is to install Developer Edition and see if it happens there or refresh your existing profile.

Tried this too, refreshed my Firefox couple times but it didn't work either :/

It happens to new profiles without any modifications? Does it still happen in Troubleshoot Mode?

Try disabling any third-party antivirus software.

It happens to new profiles without any modifications? Does it still happen in Troubleshoot Mode? Try disabling any third-party antivirus software.

It's not happening in Troubleshoot mode. I guess there's something wrong with extensions right? I also turned on toolkit.legacyUserProfileCustomizations.stylesheets setting at about:config to set custom background at newtab.

Also I noticed that, V-Sync is not working in troubleshoot mode.

Edit: I think the problem causing because of uBlock Origin, I disabled it and now it looks a bit better.

Edit2: No, I installed another adblocker (adguard) but it's still happening. Freezing every time also it freezes when I write something in whatsapp web.

It sounds like an issue with your graphics drivers, it should work with hardware acceleration disabled.

If you want hardware acceleration:

• Update your graphics drivers to the latest version from the manufacturer's site.
• Go to about:config in the address bar and try changing gfx.webrender.compositor to false then restart the browser.
• Use mozregression to find exactly when it stopped working between version 116 and 117 to help identify the problem.

It sounds like an issue with your graphics drivers, it should work with hardware acceleration disabled. If you want hardware acceleration:

• Update your graphics drivers to the latest version from the manufacturer's site.
• Go to about:config in the address bar and try changing gfx.webrender.compositor to false then restart the browser.
• Use mozregression to find exactly when it stopped working between version 116 and 117 to help identify the problem.

Now it makes completely crash to video driver I think. I did this, then restarted browser. After using it for a short time and minimizing it, I maximized it again, but suddenly the screen went black (the entire computer screen) and then came back again. All custom themes in the browser had been reset (including the ones I bought from the store).

Today, I uninstalled Firefox because I couldn't find any solution and installed ESR 115.02 version and it works perfectly fine. No crashes, no freezes, quick launch, better performance.

You can test Nightly builds between 2023-06-05 (115) and 2023-07-31 (117) to find when it broke.

https://archive.mozilla.org/pub/firefox/nightly/2023/