Firefox Community Forum

Hi everyone, I've been experiencing a persistent issue where my Firefox (Windows 10) randomly crashes or closes. I recently noticed that this always happens when a JSON file appears in the following directory: C:\Program Files\Mozilla Firefox\distribution The strange thing is that this file shouldn't even be there, as this is my personal computer and it is not managed by any organization. I have already tried deleting or renaming the file, but after a seemingly random period, it gets recreated automatically. Here’s what I have tried so far, without success: - Deleting/renaming the file - Checking the registry at HKEY_LOCAL_MACHINE\Software\Policies\Mozilla\Firefox (but the "Mozilla" folder does not exist there) - I have never used any third-party antivirus software (only Windows Defender) Does anyone have an idea where this file might be coming from or how I can prevent it from being recreated? I’m not very tech-savvy, so I would greatly appreciate simple explanations or step-by-step instructions. Thanks in advance for any help!

For years I had my Firefox sync working fine between Win10 PC, Android and several Win10 laptops. However yesterday I installed Windows 11 on the same PC I have Windows 10 (bought new disk) just to have a fresh install. Started with installing firefox - and here when problems begin. It couldn't let me log in into Sync, I was being immediately logged out ("Account disconnected"). Somehow I managed to log in, but then all my previous data was erased (passwords, bookmarks). I thought ok, maybe later it's gonna sync. Started installing extensions, saved one password. When trying to sync tabs with Android phone it didn't work, it couldn't see any tabs (but it could share tabs between devices!). On Android I still have old passwords and bookmarks saved, same as on old Win10 (on which I got logged out). Alright - it didn't sync after restart so I removed Firefox profile on machine, started again with logging in - and it synced only ONE password that I saved previously on same Win11 machine, with extensions I freshly installed back then. So it saved to sync improper data, forgetting about old? Logged out from all of my machines in Firefox Account. Now I'm back to my original machine on Windows 10. And what? I can't log in! Same error as on Win11 after install - "Account disconnected". Checked about:sync-log and found error logs - pasted into "Troubleshooting information" of this post.

Thanks

When signing in to websites, firefox offers e-mail address options that havebeen used before on that site. But right now it keeps offering two, one of which is incorrect, and I thought there was a way to fix that, but right now I cannot remember it.

This is explicitly for sites where I have told firefox *not* to save the password, and it is offering up potential email/login. entries *only*.

I do not want to tell firefox to not offer to autofill anything ever, because that saves time when the entries are correct. but here they are *not* correct and I need to clear them for this one specific website.

How do I do that?

My wife's Firefox was triggered from an e-mail link and in the process got updated to release 141.0 The result is that the tabs from the previous verion have not loaded. Can I still recover them?

It's a bit weird, I got the thing you get when you migrate to a new browser - asking if you'd like to migrate history and bookmarks. I closed it because I've used Firefox for years.

When Firefox opened proper, I got a tab asking to restore the previous session, along with a "Welcome to Firefox" tab. As well I got a few popups for other things, basically just stuff you see when you open Firefox for the first time. A couple of extensions opened up a landing page that should only open when you first install them.

All my bookmarks and browser history is there. The settings have all been reset to default. The extensions are there but all of their storage seems to be gone, like my dark reader extension no longer has the exception sites on it. Ublock has the ad count reset and most importantly all my custom rules are gone! I have spent years making hundreds of custom rules, and quite a few took hours to get right. I am sad about losing that.

Does anyone know what might have happened?

When I was looking at my about:config to see I saw these things in the modified settings.

there's quite a few settings here and IDK which are relevant. The ones in the pictures where just the first couple and I show them because they seem to have something to do with this situation "auto migrated" - when it seems like the browser did this because it thinks it migrated, the first screen I got was asking if I'd like to transfer my bookmarks and history (and good thing I closed it,or it might have deleted those too).

Hello, I am currently using Firefox Beta and I would like to switch to the regular Firefox Release without losing any of my data (browsing history, bookmarks, passwords, add-ons, and settings). I would appreciate guidance on the safest recommended method. Specifically:

Is it safe to install the Release version over Firefox Beta, or could this cause data loss or profile conflicts?

What is the best way to create a full backup of my Firefox profile beforehand?

Should I expect any issues with add-ons after moving from Beta to Release?

Do you recommend enabling Firefox Sync as an additional safeguard, or is a profile backup enough?

In case something goes wrong, what are the recommended recovery steps?

My setup:

Operating System: [windows 10 ]

Thank you for your assistance.

Hi all,

I'm using Firefox 125.0 (64-bit) on Fedora and for file downloads, I have the options "Ask whether to open or save files" and "Always ask you where to save files" enabled.

This basically works, Firefox opens a file selection dialog and I can select where I want to save my downloads - so far, so good.

The weird thing is, the default location that is shown in this dialog seems to change every time I download a file. I would expect to see the last download location as the default option, but that is not what happens.

When I check about:config, I can see the last used download path is saved as browser.download.lastDir perfectly fine, but it is not set as the default for the next download.

Is there a parameter I can set so this last path is used again?

Thanks,

M.

After an update of both macOS (to macOS Sequoia 15.0.1) and Firefox Developer Edition (to 132.0b3 (aarch64)), the Bookmarks Toolbar stopped working. The same issue appeared on my Windows PC.

Bookmarks toolbar is visible, I can show and hide it but it does not display any of my saved bookmarks. Luckily, they were not deleted and I still can access them via Bookmarks Menu, which is less than optimal.

The Drag&Drop functionality does not work either. When I grab the opened Tab, drag it on the Toolbar and release it, the Tab gets opened in the new browser window and it's not saved.

Right now i love my HDR content in most scenarios, except on a few sites where its just bad. Is it possible to be able to block it on certain sites where you dont want to apply it?

In English, the meaning of this error is: Title: Configuration error Content: Failed to read configuration file. Please contact your system administrator.

I had this error for a long time. But it's not too serious. Just hit ok and I can use all the recovery tabs as before without any problems. But every time I open windows and open the browser, this message appears. I feel very uncomfortable and tired without knowing why. Even reinstalling the browser didn't fix the problem, I tried it before and lost my favorite browser theme. And 1 more thing if someone can explain. If it can't read the configuration file, how can I still use the browser? What does that configuration file do?

This message only appears when I have not opened the Firefox browser on my computer. If I already have the tab, I can open another firefox browser without that message appearing. Only when I close all tabs. Open it again and it will appear. And click ok to use normally.

In May 2025 all browsers should have removed the default styling for the h1 element when it is nested in a sectioning element (article, aside, nav, section). I went into Firefox Dev Editions user-agent style sheet and noticed that the styling for nested h1 elements is still the same. I'm wondering why that is the case, since I was under the impression that all the major browsers had completed make the necessary adjustments at the end of May 2025.

Sorry for my language.

The latest versions of Firefox 141 (and 142 beta 1) do not allow the Windows taskbar to appear when I move the mouse to the bottom of the screen. This happens on Windows 10 with the auto-hide taskbar setting enabled. In previous Firefox versions, this worked fine (except for one older version where it briefly broke). I’m not running Firefox in fullscreen mode, and I have no modifications or themes that could interfere. I tested this on a fresh, clean installation of Firefox — the issue still occurs. After downgrading to versions 140 and 139, everything works correctly again. Interestingly, I also tested the Firefox 141 Release Candidate Build 1 from here: 🔗 https://ftp.mozilla.org/pub/firefox/candidates/141.0-candidates/ In that version, the issue only occurred in private browsing mode. Could someone please help me resolve this or confirm it as a bug? Thanks in advance!

Just updated my Mozilla Developer and it removed my bookmarks (the tab is visible but has no bookmarks, and restoring them from backup doesn't do anything) also the extention button is for some reason on the left side (it was on the right side) and the "+" button was missing, had to re-enable it (AND IT'S ALSO ON THE LEFT SIDE FOR SOME REASON)

Wtf happened

Hello! After the recent update, any text I insert remains without spaces and all words are written together. I disabled all extensions: no result. The problem did not occur in other browsers.

Up to 126.0b9, files with encoded URLs in their filenames downloaded normally. As of 127 onward, however, it gets changed to _3A instead of %3A, etc. Is there a setting somewhere in config to revert this?

Example:

Supposed to be: test [sound=https%3A%2F%2Ffiles.catbox.moe%2Fe547nk.mp3].png Downloads as: test [sound=https_3A_2F_2Ffiles.catbox.moe_2Fe547nk.mp3].png