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Hi folks

When I tried to start up Thunderbird this evening, it has taken me to a set-up page. I seem to have lost all the settings, all my previous (about 3000 !) e-mails in my Inbox.

I obviously don't really want to set it all up again, but it has been working for years without a problem, and then suddenly this happens. I had now a 'warning' message saying that Mozilla Thunderbird wants to make changes to your computer - do you accept? I don't want it to make any changes unless it is to revert back to how it was.

Can anybody help me?

Thanks.

I have installed Thunderbird on a new computer and copied my profile from the old computer as per instructions on the Mozilla site. However on the install on the new computer the LOCAL FOLDERS, sub folders which I use as archive storage do not contain the messages as per the my old computer. The sub folders are named correctly.

I have attached photos of the sub folders from the old computer showing data in the sub folder and also the new computer showing no data.

Please advise how to retrieve the data for the new computer.

Good day,

I'd like to start by thanking the Mozilla Firefox dev team for the newest iteration of the profiles feature. I think it's great.

One area where I think it could use improvement from usability perspective is a way to launch a specific profile via the right-click menu when using the taskbar icon. Currently, using the "Choose a profile when Firefox opens" only gives users the option to select the profile on the initial launch of Firefox. After that if the user opens a new window via the taskbar, the most recently opened profile is automatically chosen.

I managed to find a "hack" to add the requested capability. It seems adding an action to the "firefox.desktop" file in the "/usr/share/applications/" directory works the way I'd like it to.

Modifications to "firefox.desktop" Changed line 12 to: Actions=choose-profile;new-window;new-private-window;open-profile-manager; Added lines 529 - 534 (before Desktop Action new-window): [Desktop Action choose-profile] Exec=firefox --new-instance Name=Choose Profile Name[en_US]=Choose Profile Name[en_CA]=Choose Profile Name[en_GB]=Choose Profile

The end result is a new option available when right clicking the taskbar that opens the new profile selector. Screencaps of options before and after attached. I imagine that users will need to have the "Choose a profile when Firefox opens" enabled for this to work as expected, but would like someone from Mozilla to confirm this.

Would like to request that this option be built into Firefox going forward, so there's no need for users to "tweak" it to get this functionality.

How can I transfer my bookmarks to the new version of Firefox. The bookmarks are still available from the drop-down top bar "bookmarks" but they don't show on the Firefox page. I don't know how to get to the "about:profiles" page to change back to the profile that shows my bookmarks toolbar.

[Profile2] Name=default-release IsRelative=1 Path=Profiles/dzsmofpl.default-release [Profile1] Name=default IsRelative=1 Path=Profiles/g92ibtwu.default Default=1 [Profile0] Name=default-esr IsRelative=1 Path=Profiles/2i2jua4d.default-esr [General] StartWithLastProfile=1 Version=2 [Install712DAF5A23ABECDC] Default=Profiles/2i2jua4d.default-esr Locked=1 [InstallFEE05927A5AEB8AE] Default=Profiles/dzsmofpl.default-release Locked=1

I *think* I've followed the instructions, but I am unsuccessful in moving Thunderbird Profile to new PC. I copied old profile to external drive. I opened Thunderbird on new PC and found Profile folder. I went up 3 levels and pasted old profile from external drive into folder on new PC. But my old data have not moved. When I go into new Thunderbird and choose "open profile folder", it shows me 3 files: the two that the system created in the new download, plus the old Profile that I pasted there. The new version of Thunderbird uses the "new download" profile as the default. What am I doing wrong? Thanx!

I'm running Firefox 122.0.1 on a Windows 10 desktop PC, with a profile which includes a userChrome.css file which makes several layout and cosmetic changes.

I also have a laptop (also Windows 10) which has an old Firefox 97.0.1 installation, and I'd like to make the same changes on this machine which I'm used to on the main computer. I copied my desktop profile to the laptop, to the same directory as its present profile, but when I rebooted Firefox the transferred profile wasn't recognised.

While doing the transfer I received error messages about some of the folders: Destination path too long. This despite the fact that the registry flag to accept extended paths is set to 1. I had to skip several folders in order to complete the transfer.

Could this be the reason why the new profile isn't being picked up? Or is it because the two Firefoxes are of different versions?

I'd be grateful for any thoughts. Many thanks.

Hello, When I went to launch Firefox after starting up my PC this morning, I was greeted with: "Your Firefox profile cannot be loaded. It may be missing or inaccessible".

I went right to the Mozilla forums and found the help page [https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing...] . In this article it detailed how I should go into my AppData, then Mozilla, then Firefox, and look to see where my profile.ini file is. My profile.ini file was there, alongside the installs.ini and a few other folders. I attempted also to launch the profile manager using run and the "firefox.exe -P" command, but I got the same profile error as when I tried launching the app. The help page then recommended deleting the profile.ini file and then launching Firefox to hopefully remake the default profiles.ini file and enable me to launch Firefox, so I attempted that. When I tried relaunching Firefox, the profiles.ini file did not re-appear in my Firefox folder.

I then tried deleting the Firefox folder itself, and relaunching Firefox. This resulted in it being remade, but with just 2 folders left: Crash Reports and Pending Pings. Obviously that's not ideal, so I right clicked the Firefox folder and used the Windows "Previous versions" feature to restore the Firefox folder to a backup of how it was this morning. I then re-tried launching and I still got the same missing profiles error message. I also briefly attempted manually making a new profiles.ini file with notepad, and pointing it towards my Profile withing my Profiles folder, but that still resulted in the same missing profiles error.

This is basically where I am at now. I have confirmed that I do in fact see my actual profile in my "C:\Users\****\AppData\Roaming\Mozilla\Firefox\Profiles" folder, and as far as I can tell my profiles.ini file correctly points towards it. I did another reset of my Firefox folder to a backup of where I was at this morning before attempting anything. I can confirm my Windows account (Admin, and only account on the computer) has full read and write access to all Folders and files within the Mozilla folder, although I will mention some of the files in the Firefox folder were marked with the "Read-Only" attribute (not sure if that matters, but I tried unchecking those and still no luck)

As far as I can tell I have thoroughly exhausted all the easily accessible tips on the internet for solving this, so I am wondering what to try next?

TLDR: Error: Your Firefox profile cannot be loaded. It may be missing or inaccessible" Already Attempted (And failed): -deleting and prompting a remake of the profiles.ini folder -using firefox.exe -P to launch Profile manager -deleting Firefox folder to prompt a remake of that -multiple uninstalls and reinstalls of Firefox -manually remaking profiles.ini file after it didn't come back after deletion

Will link images of (1) profiles.ini file. (2) Profiles folder.

I have an old Windows 8.1 computer with Thunderbird installed and it has worked fine. I want to move my email to a new Windows 11 computer. My old Thunderbird is listed as version 115.18.0. The version on my new computer is listed as 141.0 and is listed as up to date. NOTE: On my old computer my 115.18.0 version is also listed by Thunderbird as "up to date." Apparently, Thunderbird cannot update my old computer version any more.

Here's the problem. Thunderbird's instructions for moving my email from one computer to another includes this warning: "To move your data, you can copy your profile folder to the equivalent location on your destination computer. Ensure both versions of Thunderbird are up to date or identical before attempting a transfer as otherwise it might fail."

So, since Thunderbird does not allow me to have "identical" versions on my two computers, how do I move my email from my old computer to my new computer? (I apologize if this question has already been asked and answered.)

I created multiple profiles with the new [management] feature. Amazing, I've been waiting for it for years!

If I open all my profiles I can distinguish them since they all have a different icon. I can also pin all the profiles (Keep in Dock) to the MacOS dock.

When I quit all Firefox instances, I would like to be able to immediately jump back to the desired profile.

Instead I get multiple Firefox icons (without the icon profile, that disappear after I quit Firefox). I find this inconvenient.

Hi all, I used to run two Firefox instances on the same computer, each one using a different account (as I mentioned in the Subject), but I don't remember how I managed this, so now that I moved to a new computer I can't reproduce it! Thanks for helping, if anyone knows. Regards, Mike

I am having trouble moving Thunderbird data from one computer to another. The first computer is Windows 10 32-bit that has been running T-Bird 140.3.0esr for several years. The second is Windows 11 64-bit running T-Bird's latest version. I tried both procedures cited in the Mozilla article at https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer.

I first did the 2nd method cited -- Win 10 to Win 11. It worked but the new computer is missing Local Folders and contacts organized as groups.

I then did the 1st procedure cited, using copy and paste commands. It did not work at all and now T-Bird will not load. I get this message: "Your Thunderbird profile cannot be loaded. It may be missing or inaccessible."

So, different operating systems with different bit specs and different T-Bird versions.

I thought of updating the Win 10 computer to T-Bird's current version and then doing the Win-10-to-Win-11 copy/move procedure but thought it best to ask here first. Thanks for any help.

I'm setting up Firefox on a new computer. I haven't done this for a while and the interface has changed, so I'm not sure how it works.

I want to move my Firefox profile to a directory in the Documents library to simplify backup. Following the Mozilla instructions I found, I opened about:profiles and clicked the Create New Profile button. I deleted the contents of the directory that Create New Profile created and copied the contents of the default profile directory to it. The last step is to tell Firefox to use my new profile instead of its default.

But the about:profile page lists three profiles: default-release, default, and my new one. The first two have a Set as default profile button; the last does not. So it appears that I can tell Firefox to use the default-release profile or the default profile, but there's no way I can tell it to use my new profile. I can only Launch profile in new browser -- presumably something I'll have to do every time I run Firefox.

This makes no sense. How can I tell Firefox to use my new profile -- not to launch a new browser with it, but to use it, period? If I can't, why can't I? Every version of Firefox I've ever installed up to now allowed this.

Also, the default-release profile section of about:profiles has the note "This is the profile in use and it cannot be deleted." So it appears that Firefox uses the default-release profile instead of the default profile as its default profile. What is the default-release profile? Why isn't the default profile the default profile?

Hello,

We are trying to automate updating Firefox ESR from 32bit to 64bit. There seems to be an issue with getting user's profiles to properly migrate for ESR. If we do a plain 32bit uninstall and 64bit installation, a new "default-esr-1" profile gets created (which is expected behavior from these Mozilla docs for new installs). But, when we set the MOZ_LEGACY_PROFILES=1 policy, this reverts to using the "default" profile instead of "default-esr" profile that was previously in use.

Are there any known ways around this which does not require user intervention to manually change back to the "default-esr" profile?

Thank you

I am troubleshooting a problem that arose after I migrated a Thunderbird mail account from an old Win10 64-bit PC to a new Win11 64-bit PC.

I installed TB on the new machine and opened the program without doing anything else, then closed the program. TB created installs.ini and profiles.ini files, both with the following as the last line:

Locked=1

This line had not been in either .ini file on the old installation.

I edited these files to point to the backed-up TB profile from the old machine, but I decided to leave the Locked=1 line in the .ini files.

Was this a mistake? I have a strange problem with the new installation, which I won't report until I understand what the "Locked=1" means, and whether I was ill-advised to leave it/them in. Fortunately there has been no evident loss of mail data.

Thanks in advance, Phil

Oct 23, 2025, 19:35 CST

I FINALLY was able to find the original profile, all messages in the In Box, plus all folders with their contents. 'Lost' when our ISP's ' tech support person ' had me close/remove the TB POP3 account and create an IMAP account).

I need to merge the new small profile (In Box & with basic folders) into - onto the BIG, original, profile. So each time I get/check mail everything goes to, ends up in, the Thunderbird account containing all the OLD data and new working account.

Please remember I am barely TB literate, so start at 1 (A), not 27 (Z)& no tech words. Nor acronyms please.

Thanks! Remain in GOOD health, be WELL, 'n be

• • SAFE!**

Robin

My version of Firefox wont save History, Bookmarks or Downloads. I've made sure the privacy settings are correct and have tried reinstalling Firefox several times. It also wont let me drag a link from the address bar to the bookmark bar anymore like it used to. Any help with this would be much appreciated... Thanks!

Hello Thunderbird Team I am facing a crisis and am praying you can help me. I have been using Thunderbird since 2021. I had setup my account and archives by year containing messages in Folders (Inbox, Sent & Deleted). During a recent laptop migration, I accidentally deleted my profile on my old laptop. I immdeiately recreated it. However now all email stored in my inbox has disappeared. Second, I cannot seem to locate the archives. So I have 2 requests for urgent support: 1. How do I locate the messages in my inbox prior to deleting my profile? 2. How can I recreate the archive with folders? I can see that the profile folder is a massive 22 GB. So the data is there somewhere. Please help me recreate my email profile so I doi not face a business crisis. Thank You Warm regards Milind

A newer version of Thunderbird may have made changes to your profile which are no longer compatible with this older version. Use this profile only with that newer version, or create a new profile for this installation of Thunderbird. Creating a new profile requires setting up your accounts, calendars and add-ons again.

More information…

THIS NEEDS AN OPTION TO CONTINUE USING OLD PROFILE. YOU JUST MADE THUNDERBIRD USELESS TO ME. DO NOT KNOW HOW TO CREARE A NEW PROFILE. SHOULD NOT NEED TO. CAN NOT START IT AFTER MANY YEARS OF USE. PREFERRED OLD VERSION OF ABOUT 5 YEARS AGO. JAY

I have backed up the data regularly before, but in the new Windows 11 pc, I cannot find the data.

It used to be "C:\Users\Jim\AppData\Roaming\Thunderbird\Profiles\itfho9h2.default" on the old Windows PC which went bonkers. Now should be "C:\Users\Jim\AppData\Roaming\Thunderbird\Profiles\i3ls19ra.default-esr", but when looking in the "C:\Users\Jim\AppData\Roaming\" folder, Thunderbird folder is not there with the others. But that is where Thunderbird data is supposed to be according to Account Settings, Message Storage, Local Directory.

So, how do I find where the data is so that I can back it up?

Thanks.