Yonke imikhiqizo Community Forum

This is Firefox 142.0.1 on Windows 10. I prefer to have a local copy of the Firefox profile saved to a USB stick as a simple backup and for copying to another PC if necessary. I have been doing this for years, but now I am unable to do so because Windows gives me an "access denied" error for all of the files in the top-level profile directory. I cannot even open them in Administrator mode. If I try to copy the profile directory as described in your help pages, it says that I need permission from the account that I am logged in as in order to access the files! I have been using Windows since version 3.0 and I cannot understand what Firefox has done to make the profile inaccessible to everything but itself. Obviously, Firefox is able to read the files without additional permissions, so why can't I?

I am running Windows 10 and am going to upgrade to Windows 11. To do this I need to save my Thunderbird system emails and folders, to enable me to reformat my disk drive. I can then fresh install Win 11 and Thunderbird to get my email working again. Advice as to what to save (profile?) in Thunderbird. Then putting this info into the new install of TB. Many thanks, Paul.

I only have one profile in Thunderbird. It has grown to 52 GB. I often transfer my profile between a light weight laptop and my desktop. I am trying to delete files to reduce the overall size of my profile down.

I found a file with a .pcv ending, dated 2018 (we are now in 2025) - can I delete it.

Also is there a spot where the various file formats are discussed ie MSF file, NSTMP files, .pcv, .sqlite, .sqlite-wal, sqlite-snm, metadata-v2

I got a warning that I am running out of disk space, on checking I found the Thunderbird_profile_backup.zip is currently 297Gb. I must do something about this, can I delete it, or is there another way to reduce this rediculous size?

I am running the latest version 140.3.0esr (64bit) I have two IMAP accounts, and I do download some mail into local folders, but nothing near this sort of quantity. Any help or suggestions would be most welcome.

Hello, I would like to move my TB profile folder from my Mac OS internal drive (its default location) to an external drive (I need the space on my internal drive which is getting too full). It is not for a backup, it is for the working profile folder. How should I proceed ? Thank you

I have my personal account on firefox and it syncs everything but I want to be able to do the same for my business account. when I sign out of my personal and try to sign in to my business it says I can't. I try to re-set my password and it says I have to use the "primary" account email. It does not accept my business account.

How do I get firefox account for my business email?

Thank you

The article explaining why one should not downgrade ignores a critical reason why one needs to downgrade and that is when it turns out that the new version breaks an existing website!

I got bitten by this when Firefox "upgraded" me to V143 after which point the ticket system I use to support my customers stopped working. That same ticket system continues to work fine in Safari, Edge, Chrome and Brave, etc.

Worse, when one does try to downgrade, the old profile gets removed which means you lose EVERYTHING you had (tabs, bookmarks and presumably all the settings and saved passwords, etc). You need to be keeping the old profiles around so that they can be accessed again should someone NEED to downgrade. Fortunately I was able to use Time Machine to recover the old profile --- but somebody just didn't think this through.

Much as I have loved Firefox over the years, I'm starting to feel that it's time to give up on it and move to something else.

Turning off automatic updates is not a solution because eventually one will choose to upgrade manually and most people won't remember to make a copy of their existing profile. Should one then encounter a problem, you're back to square one

Very disappointing .

I have problems migrating my Windows 10 Thunderbird profile to a new computer running Linux.

On the new computer, I want to put the profile into a custom folder, not the standard folder (which would be /home/torben/.var/app/net.thunderbird.Thunderbird/.thunderbird in my case)

Here's what I did:

I installed Thunderbird 128.13.0esr under Fedora Linux 42 using flatpak.

Upon first startup, I aborted the mail account setup process

Opened Help/Troubleshooting information ... about:profiles

Create new profile ... Choose folder (I am translating everything from my German language version)

--> That's where an error message occurs: "/home/torben/.thunderbird not found ..." (interestingly, this folder simply does not exist (yes, I know how to view hidden files) although about:profiles also says that the "root folder" of the two already existing profiles default and default-esr is inside /home/torben/.thunderbird !?)

Nevertheless, in the profile assistant I can choose the folder (/home/torben/Dokumente/Gemeinsam/Documents/Briefe/Thunderbird_Profiles/tj63nudj.default) containing my migrated profile

The profile assistant tells me that my personal settings and data will be saved in /run/user/1000/doc/e9915464/tj63nudj.default (?)

After finishing the profile assistant, I can see the newly created profile in about:profiles, but it says "This profile is currently used by another application and therefore cannot be deleted" (what other application?)

I click "normal re-start" in the upper right corner of the about:profiles tab

After restarting, I open the about:profiles tab again. Now I can click on "run profile" under my newly created profile and Thunderbird opens a new window where everything works fine: All the migrated mails are there, I can log into my usual imap accounts etc.

I can close both windows, restart Thunderbird again and again and everything stays fine

BUT after some time (about 10 minutes) Thunderbird won't (re)start anymore and displays this error:

"Thunderbird is already running, but is not responding. To use Thunderbird, you must first close the existing Thunderbird process, restart your device, or use a different profile."

The error persists after rebooting.

This error seems to be related to that whole manual migration process, because when I simply follow that mail account setup assistant after a clean re-install of Thunderbird, I can keep using the program without any issues (although the /home/torben/.thunderbird folder isn't created either) ...

Would be very grateful if someone had an idea how to solve this problem ... Thanks in advance!

My c: disk is getting full, so I decided to transfer my Thunderbird profile to d: . My old Tbird profile has profile folders for two POP accounts and two IMAP accounts. I managed to copy the profile and set up new accounts and now emails work, but in the process I disconnected the old profile on c: . When trying to create a new account on c: (so that I can access the old profile to delete old mails and get more space) I run into either "incoming server already exists" or I am asked a password which I can't find.

Any help would be highly appreciated! Should I just delete the old profile, or is there a procedure to safely remove it? Or is a Tbird reinstall in order? Thanks!

I do not want to use Thunderbird anymore. So I deleted my two mail accounts, but thunderbird still remembers them - this I do not want. And how can I close thunderbird definitely, thunderbird also forgot already the main password... Thanks for help!

My windows 10 PC died. I copied the the profiles folder from the old appdata/roaming/Thunderbird to the new Win11 PC, but TB does not pick it up, asking to create a new account "John Doe". Any ideas? Best, K.

I am using a very old system that is running out of storage space. There is an 8.73 GB folder that I would like to empty to free up space. C:\dtemp\Profiles contains several folders that were created 10.27.21: 2qzfs15q.default, eybandys.default, f81zrqic.default-release, pctnmazu.default-release-1, and yns5cb3s.default-release.

Can I delete any of these folders?

I don't have a Profiles menu under the Account button on the main toolbar. My Firefox was just updated and the update tab info talked about the new profiles feature as if it was available. Is this rolling out in phases or should I be seeing it?

I have version 144.0, updated on 10/14/2025.

Thanks.

How can I move Thunderbird 140 from Windows 10 to Windows 11 computer? The latest Thunderbird download is 143. But it doesn't recognize my copied profiles, in folders /Local and /Roaming. I have edited the profiles.ini to only see the one profile that I copied.

I migrated from Win10 (v140 ESR 32-bit) to Win11 (v143 64-bit). I copied both /Local and /Roaming folders. Thunderbird keeps showing “Account Setup.” profiles.ini contains two [Install...] blocks and I already removed them.

Can you help reset the install hash or rebuild the installs.ini file live with me? — that was a suggestion from a tech at JustAnswer.com

Thank you.

Bonjour, J'ai essayé à plusieurs reprises d'installer Thunderbird (a chaque fois 1 don est requis) mais à chaque fois le même message s'affiche : "Le profil Thunderbird ne peut être chargé. Il est peut-être manquant ou inaccessible". Une première fois l'installation avait fonctionné mas j'ai essayé de modifier le profil afin qu'ils puissent reprendre le carnet existant sur mon ancien ordinateur. Aujourd'hui je suis bloqué. Avez vous 1 solution à me proposer ? Merci

Hello, I have two profiles, one for work and one personal. I used two different email addresses for them. How can I merge these together for the new profile management?

I want to back up the Local and Roaming folders, in case something goes wrong. But I am getting an error code 80070057. I ran DISM Restore Health, but that did not change anything.

Do I have to be logged into an account to use profiles? I'm on my work computer on which I don't log into my account and "Profiles" option does not show up on my toolbar.