Firefox Community Forum

I've been using the extension "Tree Style Tab" and "TST Colored Tabs." I've been looking for a way to disable the native Firefox tab bar, whether on top of the window or to the left side. I haven't been successful on my own.

After a couple of hours troubleshooting this with CoPilot, It suggested I post the following short summary:

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Firefox 152.0.6 (64-bit) about:profiles shows active profile: C:\Users\dmerc\AppData\Roaming\Mozilla\Firefox\Profiles\usm8kxcr.default-release

Opening that directory from about:support shows an empty folder.

profiles.ini references: agwp164m.default-release

userChrome.css loads correctly in a separate profile but not in the profile containing my current extensions and history.

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The details of how it came to this conclusion:

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Based on everything you've found:

The profile with your current extensions and recent history is reported as: usm8kxcr.default-release

Opening that profile folder shows an empty directory. The only other real profile on disk is: agwp164m.default-release

We successfully proved userChrome.css loads in a different test profile (Profile 1) because the toolbar turned red. Therefore, the CSS mechanism itself works on your machine.

My conclusion is that your Firefox profile registration has become inconsistent. Firefox appears to be using a profile that does not correspond cleanly to the profile folders you're seeing in Explorer. At this point I would:

Back up the entire folder: (NOTE: DONE - backed to to another drive) C:\Users\dmerc\AppData\Roaming\Mozilla\Firefox

Keep using the profile that contains your extensions and recent history. Avoid deleting any profiles or profile folders.

Post the details you've collected to either: the Mozilla Support forum, or r/firefox

The key facts to provide are: Firefox 152.0.6 (64-bit)about:profiles shows active profile: C:\Users\dmerc\AppData\Roaming\Mozilla\Firefox\Profiles\usm8kxcr.default-release.

Opening that directory from about:support shows an empty folder.

profiles.ini references: agwp164m.default-release

userChrome.css loads correctly in a separate profile but not in the profile containing my current extensions and history. \ Those facts point to a profile-management issue rather than a Tree Style Tab or CSS issue.

The good news is that your current extensions and recent history are still accessible, so this doesn't look like data loss. The profile mapping itself needs to be untangled before custom CSS can reliably be applied.

=

It also suggested not copying any folders and files between profiles for now.

Hello,

My little brother signed me out of my mozilla account while trying to login to his school account using my computer yesterday. Now, even after signing his account out AND removing his account entirely from my firefox, I'm unable to login using my credentials on the "original profile" which is what I've always used. This is the message I get when trying to login:

This profile was previously synced to a different account To keep your data organized and secure, each Firefox profile can only be synced to one account. To sign in using (email)@gmail.com, create a new profile.

He wasn't even able to fully login with his account, and even after completely removing his account from my firefox (as far as I know) I'm not able to sign into the original profile at *all*, even though that's what I've always used. Does anyone have a solution for this?

i have been with Firefox since it started and now you have changed it to the pint where i am leaving it . i want my original profile i do not want any old profiles where i lose everything like bookmarks and everything i have added extensions you forced me to leave to leave unless i can keep the old profile always see you Firefox you have just forced me to go to chrome thanks a lot unless i can keep the old profile original prpofile and still update the versions as need ed other wise good bye to you

I had a problem where FF 140.0 would not update, and in trying to get FF yo update, I used a re-install tool to which I was pointed in my problem report. This caused FF to wipe out my configuration, and I lost all my windows and tabs. I have gone to

    \Appdata\Roaming\Mozilla\Firefox\Proifiles\abnfpged.default

cleared all of the data therein, and restored that directory from a backup I made last Monday. But I cannot get FF to use that directory. "about:profiles" shows only two profiles, but the Profiles directory has five profiles:

03/10/2026 09:39 AM <DIR> qf00ka5x.default 03/10/2026 09:39 AM <DIR> v842ceue.default-release 04/11/2026 09:16 PM <DIR> .. 04/11/2026 09:16 PM <DIR> . 04/12/2026 03:08 PM <DIR> abnfpged.default 04/12/2026 06:29 PM <DIR> jdfj91sd.default-release-1775960183850 04/12/2026 06:48 PM <DIR> f1jq4mlq.default

Only the profiles beginning with "j" and "f1" are seen in the "about:profiles" screenshot I have attached. And I have attached a screenshot of my profiles.ini file. Also, in the abnfpged.default directory I restored, where is the list of all of my open windows and tabs? FF used to keep that in a sessionstore.jsonlz4 file, but that file is only written when FF closes. I tried to save a copy when I was having problems, but I stored the copy in the same directory, which FF changed during the re-install process. Here is my profiles,.ini file:

[Install308046B0AF4A39CB] Default=Profiles/jdfj91sd.default-release-1775960183850 Locked=1

[Profile1] Name=default IsRelative=1 Path=Profiles/f1jq4mlq.default

[Profile0] Name=default-release IsRelative=1 Path=Profiles/jdfj91sd.default-release-1775960183850

[Install641D10338ABA448D] Default=Profiles/abnfpged.default Default=1 IsRelative=1 Locked=1

[General]

StartWithLastProfile=1

Version=2

[BackgroundTasksProfiles] MozillaBackgroundTask-308046B0AF4A39CB-defaultagent=lnvi5jn5.MozillaBackgroundTask-308046B0AF4A39CB-defaultagent

I have not worked with the ;profiles.ini file in many years, as my FF configuration has not had problems. Thanks.

Yes, I'd like to use the same account on both of my profiles.

I understand that for some users, this may be confusing.

In my case, the only reason for different profiles is that I need to use a Proxy Server for some websites, and no proxy for other websites. Manually switching proxy settings is painful, and doing so causes traffic for my other tabs/windows to go to the proxy, which I do not want.

I have a main (set of) windows (and its tabs) going straight to the internet, then I have a separate window (and its tabs) configured to go through a proxy (SOCKS5 in this case). I want all other settings, bookmarks, passwords, etc. to be identical to both. I end up having to logout of my main profile, log into the other profile to sync settings, log out of there, and log back into my main profile.

Is there a valid technical reason why an account on the same FireFox installation cannot be shared between two profiles?

I can do this on multiple computers (same account, different computers/profile), seems odd it is restricted to not allow on the same computer.

I have an alternative solution: Install FireFox natively, then install FireFox as AUR or FlatPak, but not sure this will collide as this both uses the same profile directory. Hum...

Wayne

The Issue: I want to copy all bookmarks/Logins/PW from original into two additional already created but not used Profiles. Hence, I have created 3 desired profiles.

I want to copy into each profile the "Original" Bookmarks/Logins/PW nothing else matters to me, i can go to each profile and modify its settings after that and I have read the device Sync considerations.

At this stage, do I abandon the already created 2 additional Profiles and follow the Copy to New Profile procedures outlined in FAQs?

The benefit to my current state is I could copy in "Original" Bookmarks/Logins/PWs to the newly create profiles that are vacant I could then go into each profile to delete the non-relevant data.'

I have read the FAQ differences for Containers vs Profiles and still feel Profiles is best for me. I have also read Sync and the associated threads in FAQ. I have also read Copy from "Original" profile but it seems to apply when creating a Profile.

In the Original profil, I have three Bookmark sub-folders and over 200 bookmarks, plus over 480 Login/PWs. I wanted something like Profiles feature, to put my personal (PW, Bookmarks & Logins) into its own areas' Profile. The use case is Original I use for learning, Personal for banking and medical, the 3rd I have setup one Not For Profit Organization Profile. Each has relevant bookmarks/Logins.PW.

So I created my Profiles. Then realized the PW/Bookmarks/Logins are truly separated.

I'm a bit puzzled here. Initially, I tried to use the new built-in VPN for only a single domain. That doesn't work at all. Until it does, I tried to get it through other ways. Containers don't work, private windows neither, they both just inherit the global VPN setting.

So I moved on to profiles. The web found me a Mozilla support topic that suggested to open about:profiles and create a new one. Did that, opened a window for it, but couldn't get it to reopen on any easy path, just through opening about:profiles and clicking one of the many buttons again.

Then I found another description that used the "Profiles" menu. Never seen that before (probably because the menu bar isn't visible by default). Created a new profile there, too, and opened it. After restarting Firefox, all was gone! My original profile with everything was totally inaccessible, like a full data loss. Google search AI in a Chrome browser helped me out and explained what I need to do (in about:profiles, select the old one as default, then restart) to get my environment back. After that I deleted all newly created profiles and then their directories again.

Started over with a new "new" profile and continued there. Now I wanted to activate the VPN in there. It asked me to log in again, which was a good sign because finally I got a Firefox window that didn't know about the other window. But then the next failure: I couldn't log in with my credentials because that profile was already used in the other window/profile. Again, they're not completely separated from each other and there's some hidden link between them.

So, do I need a new Firefox/Mozilla account only for a separate Firefox profile? I can happily use my one account on different devices but not on the same device? Can I unlink the main profile from my account again? I don't see a logout button anywhere, I'm just logged in invisibly.

Just this week I found it was impossible to get to firefox browsing until I chose an upsetting blob as my profile. Is there anyway to skip this step or at least to change that blob to something that makes a more pleasant experience?

With the profile system, which I just used to try and fix another problem. Deleting them doesn't work I've tried manually deleting the profiles as well but they still show up in the UI and it just recreates the folder again if you try to delete it or open it. If you use the UI to try and delete it the instance and page it opens is simply blank. And now the profile I'm trying to delete isn't open. I'm trying to delete it from "original profile" and when I do it opens the a new instance of firefox with the profile I'm trying to delete with in the address bar: about:deleteprofile but the screen is empty.

I want to keep the original profile but the process is confusing to me. Can you tell me a simple way to keep the original profile or else set the original for me.

Thanks

Boyd Proctor

после обновления в панели инструментов появилась вкладка профили и она мне даром не нужна но хуже всего что теперь файрфокс каждый раз перед запуском заставляет выбирать профиль и ни какие настройки не помогают! что только не пробовал все бесполезно -- вечно выскакиевает это окно с выбором профиля! какой [edited] мог такое придумать??? и как избавится от эт ого [edited]!!! мне нужен обычный браузер каким он был до версии 150 без [edited] вкладок и [edited] ИИ

I am not a native English speaker, so I used translation. Please excuse any awkward phrasing. I previously updated my Firefox to version 150, but my tabs kept crashing roughly every 5 minutes. To solve this, I tried installing the Firefox ESR version. However, my profile had already been upgraded to the new version format, so ESR could not read my data. I then reinstalled version 150, but now I'm having profile issues again. I can access and launch my old profile through about:profiles, but I can't seem to save it directly as the default profile. I don't want to have to repeat this process every time I restart the browser. Is there a way to transfer all my data (bookmarks, saved passwords, add-ons, settings, etc.) to a new profile that works with the current version? Or, can I downgrade my profile so that ESR can read it? I have tried copying the files from %APPDATA%\Mozilla\Firefox\Profiles, but it didn't work after many attempts. Please help me. I really don't want to set everything up from scratch again. Thank you!

I have my personal account with my personal email setup in both my home PC and laptop. I want to setup a new user profile linked to a work email to hold those passwords and bookmarks separately, and be able to sync it when using my laptop as well. I would also like to be able to have both accounts open at the same time in different windows (i.e. a "work window" with the work account, and a "personal window" with my personal account)

Is this possible? How would I go about it? I looked around the about:profiles tab, but that seems to only configure profiles for my already logged in account (the personal one). I think that what I should do is create a new firefox account with my work email and give that account a profile, but I don't know if I can be logged in to 2 accounts at the same time, and I'm not sure Firefox will show me both profiles at startup, or only the ones linked to the currently logged in account. I haven't tried this because I'm unsure if I could lose my currently open tabs.

I imported my profiles from another machine to a new laptop. Now the profiles all work and I can launch into them using the shortcuts with -p "[name]" this now brings up the old wizard rather than launching directly into the profile, and the new profile manager does not see them at all.

about:profiles sees them properly.

The profiles were imported by using about:profiles to make new black profiles, then copying in the data as from the support article: http://mzl.la/1xKrFsk

Many thanks in advance for the help.

In "manage profiles" I see where to delete the extra profile that was created and I don't want. Thanks to Cetaseus1. my question is does deleting a profile delete all the bookmarks? there is an info box that warns that bookmarks will be deleted including my 30,000+ bookmarks that were rolled over to this unwanted profile that just appeared. My intent is to have one remaining profile and all my bookmarks. I am hesitant to delete a profile and loose all those bookmarks. I won't delete until Mozilla assures me that I won't lose the bookmarks in the other profile. Thanks.

MacOS 15.5

I accidentally deleted my Firefox profile not knowing its criticality. When trying to open Firefox, I receive "Profile Missing. You're Firefox profile cannot be loaded. It may be missing or inaccessible.".

1. I have uninstalled and reinstalled Firefox to no success 2. In the Library/Application Support directory, there is no Firefox or Mozilla folder 3. In the Library/Caches directory, there is no Firefox or Mozilla folder 4. I have tried opening Firefox by pressing option + click, no change in behaviour

Hi, I'm running FF 149.0 (64-bit) on Windows 11. I've used profiles for a while now and on several occassions I've "lost profiles". Currently I have three profiles which I set up and edited the icon and colour associated with each. When I launch FF I see the Profile Manager and can select any of the three and I can create a new profile which shows here. However, once in any one of the FF profiles I don't see the others - by which I mean that when I go via the hamburger lines top right and click on the current profile, the 'other profiles' section is blank. I also cannot edit the profile from using the edit pencil top right (after clicking the hamburger lines and clicking on the current profile), it takes me to about:editprofile but the page is completely blank. Confusingly, if I go to about:profiles I see two profiles, neither of which shows up in the Profile Manager! I'm going round in circles trying to understand where to edit my exisitng profiles and make sense of the five profiles that don't all show up in the same place!