Diễn đàn hỗ trợ Firefox

I need to call an executable script that I wrote when I click on a link to a file of a certain file type. I used to be able to browse to my script in order to set it as the desired application, but now I can't find any way to persuade Firefox to call my script when, for example, the linked-to file's name ends in '.dng'. Where is the list of such applications, and how do I add my script to it?

Hello, I have been aware of this issue for about a month now. I have, for example, added 3 sites to my "Block" list under "Manage Exceptions" in "Cookies and Site Data". They are not only repeatedly disappearing from the exceptions list without my input (which I suppose is the bigger issue), but even when they are present, the websites still end up storing cookies and site data for the session. These sites are Wikipedia, Bing, and DuckDuckGo.

In addition, I've also added a finance website to the "Allow" list, as the browser is set to delete cookies on quit. This website has also repeatedly disappeared from the exceptions list without my input.

My version of Firefox updates regularly via the Linux Update manager. I am also wondering if the "Forget about this site" option in the History menu generates this (at least to me) unexpected behaviour. I would expect that using the "Forget about this site" option would delete site data, cookies, and history, but not remove it from my Cookies exception list...

I've been trying to set up 2fA on my firefox account, the whole process seems to work, I downloaded the backup codes and entered one to confirm and then got confirmation that 2FA was enabled (see screenshot). However, after reloading the page 2fA is shown as being disabled and indeed if I try to log out then in again I'm not asked for a code. I've tried this a couple of times now and it does the same every time. The auth app I'm using is Aegis.

Does anyone knows why this is happening ? Thanks.

[Edit: I just saw that after each time I tried to set it up, in "recent account activity" I add an error saying "Two-step authentication failed" which doesn't really makes sense...]

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 there! The New Tab page looks great with white text, but Firefox 140.0.4 thinks my wallpaper is white, so text should be dark. I can change the body class to "activity-stream darkWallpaper" using the inspector and it works fine, but how make this change permanently?

Hi Team, I am using Linux Mint 20 Cinnamon. Cinnamon version is 4.6.6. The issue is that I was browsing and by mistake I selected one tab then dragged it for sometime and then released the tab but that created a new window and now the old windows are not visible in ALT + Tab function. The windows are showing in the Firefox task manager and also the box icon in the top right corner in that "open tabs". Now I am not able to even change the window or able to access the opened tabs. Attached the screenshot and as you can see in that there are total 4 windows showing in firefox and one as active but in the bottom on the firefox icon you can see its only 1 window. How can I access the remaining 3 windows? Found one ticket (https://support.mozilla.org/en-US/questions/1477845) in this the recommend solution does not work. When I try to click on the window 1 tabs then I do not get any response. I tried both the solution but none worked.

Thanks for the help in advance. @Mozilla team member is seeing please check and fix this bug if possible.

dear sir/madam, when i am opening work site it is not working properly it is showing secure connection failed in boss linux i update my browser but problem still continue.

I created an account on an old PC, in the account it is visible as kos-work-note, now I am on a new kos-ltop, and there is no data at all in the browser, why is that?

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!

Hello,

I can't figure out how to add a custom search shortcut, is this no longer possible in Firefox (without installing addons/extensions)?

I recall 'custom search' being more or less ubiquitous, and feel like there was an "Add" button below the Search Shortcuts UI not that long ago.

Bookmarks with keywords would be a reasonable workaround if it weren't for having to prefix the keyword to the search terms.

Thank you, Kyle

I keep a lot of tabs open (~60) in any particular session - I find it's faster in this way to get back to a site.

About every six months or so, I lose *all* these tabs because of Firefox's inadequate session backup system. It only saves two or three total backups, some of which are completely out of date. But the worst scenario is when (1) some site pops up a new window; (2) I mistakenly close my main window before the new window; (3) I open this new saved window once or twice by accident, causing my 60-tab session backup to be overwritten.

Using a third-party session manager (I have tried all the well-known ones) can mitigate this problem, but doesn't really solve it because the re-opened sessions aren't quite in the same format as Firefox sessions and so lose information. In particular, I often lose each tab's icon as well as metadata for Tree Style Tab.

Could Mozilla please consider a more robust session backup system for Firefox? All it would take (I think) is to allow the user to choose the total number of backup sessions and the frequency at which a new session is added. Thank you!

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! i was wondering why my firefox reseted after reboot. i have all the important tabs and bookmarks for my university work, chores and articles, platforms that are mandetory on my uni. also, i was tinkering with partitions before the reboot because my steam didnt want to run any games. i was guided by the chat gpt with terminal coding to do get steam working even tho i didnt solve the problem. is there any way you can help me?

Support Firefox to be able to use different tab view modes on different windows! For example, two Firefox windows on different monitors, in my situation below:

- One on a 1920*1080 hori screen, with vertical tab sidebar disabled - One on a 1080*1920 vert screen, with vertical tab sidebar enabled for this window only in this case.

It brings much more convenience, at least for situations just like mine :)