Firefox Community Forum

I was finally forced to update my Firefox to the released version. I am increasingly unable to log in to various "secure" websites with Firefox 140...1 although Chrome 106 (old, but can't update) has no problem. There are also a number of captchas that are simply invisible to firefox. Why is this happening?

https://gist.github.com/ben-j-c/6d15852955d04c9018600d15d4a8a13e

Context: Here is an animation I generate with a program I'm developing. It being an SVG makes it useful to open in a web-browser. In chromium based browsers I have smooth animation, while in firefox I get much worse performance. At larger animations the problem becomes much more apparent. This is the approximately the largest animation that firefox can handle without lagging too much.

Expected: Firefox should have comparable SVG animation performance as chromium.

Hi, Using FireFox to log into Le Chat Mistral doesn’t work on my Ubuntu 22.04 PC. I enter the email to verify the A/C then enter the code number. Next it says ‘You successfully verified your email address’ and pressing 'Continue' I go back to 'Verify your account' page and round we go again??. There is no problem on my Windows 11 laptop so what's the issue with Ubuntu or have I done something silly? Thanks

I'm using Firefox on Ubuntu, and every time the browser crashes and I reopen it, I get the "Start New Session" or "Restore Previous Session" prompt. I’ve tried both options at different times, but in either case, I find myself logged out of Gmail.

This is quite frustrating, especially considering the number of authentication steps required to log back in (e.g., 2FA, verification prompts, etc.).

It seems like session cookies or state information aren’t being properly preserved or restored after a crash. I had high hopes from Firefox in terms of privacy and stability, but this issue is seriously affecting my workflow.

Has anyone else faced this? Is there a way to ensure that sessions (especially login sessions like Gmail) are preserved after a crash?

Any help or suggestions would be appreciated!

Fix for RangeError: invalid language tag and client-side exceptions in Firefox on Linux

Hi everyone, I was experiencing persistent JavaScript errors in Firefox on Linux when loading certain modern websites (e.g., built with React or Next.js). The browser console showed messages like:

   RangeError: invalid language tag: "chrome://global/locale/intl.properties"

   A client-side exception has occurred (see the browser console for more information)
   React error #418 with minified stack traces

This happened even in Safe Mode, with all extensions disabled, cookies/cache cleared, and Enhanced Tracking Protection off. ✅ Root cause and fix:

Turns out the issue was related to missing or broken locale configuration in Firefox. To fix it:

   Open about:config

   Create a new string entry:

       Name: intl.locale.requested

       Value: en-US (or fr, en-GB, etc. — any valid locale)

   Restart Firefox

After adding this key, all affected pages started working correctly. The invalid "chrome://global/locale/intl.properties" error in intl.accept_languages disappeared as well — it seems that was just a side effect of the missing locale setting. 🔁 Summary:

If you’re seeing RangeError: invalid language tag and React crashes, try adding intl.locale.requested manually. This fixed the issue entirely for me on Linux.

Hope this helps others!

Hi all, I'm using Firefox 140.0.4 (64-bit) on Debian Trixie and I'm getting a weird behavior with the auto-complete functionality of the address bar.

If I type the first character the address gets auto filled (see 20250711_First-character-auto-fill-working.png attachment), then if I type the second character the auto filled result disappears (see 20250711_Second-character-auto-fill-NOT-working.png).

I've tried any search option combination, but results doesn't change. At the moment I'm using for the address bar just "Browsing history" (see 20250711_Address-bar-settings.png).

The correct behavior would be, as in the past, that new characters confirming the address would leave things as they are. Do you have any suggestion on how to restore the original behavior?

Many thanks,

Raoul

All of a sudden Firefox started to use alt+number (e.g. alt+3) to switch to that tab (i.e. tab 3 in my example).

Why? How do I disable this? It prevents me from typing any of the special characters that are located on alt + any number key. E.g. I can type the at-sign, not the dollar, or any such character which requires the alt-modifier and a number.