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After Windows installed an update in the middle of the night I can't open Thunderbird and I've tried uninstalling it and reinstalling with success.

It says: Thunderbird is already running, but is not responding. The old Thunderbird process must be closed to open a new window.

I've rebooted the PC, shut down the PC, ended the task and still nothing. It seem that Thunderbird didn't shut down correctly and the system still thinks that it's open and running. Anyone know how I can fix this issue?

Thanks,

Gregg

At startup of Thunderbird, get error related to Outlook which I do not use. Get message - "UserHasNoMailboxandNoLicenseAssignedError"

How do I get rid of this error, has been present since last esr release and expected it to go away with new release - did not. Do I have to reinstall Thunderbird to clear.

my windows 10 PC was saving my bookmarks perfectly and storing in bookmarks after pressing the "save" star (star turns black) until dec 4 but its no longer putting them in the bookmarks menu anymore even though star turned black? then also after numerous attempts to no avail a "edit" pop up came up and after pressing that it did not even come up with the drop down "save" option just a big nothing. My email is: [edited email from community support forum]. Can you help with this. (P.S. The article "Cant add change or save bookmarks" did not help either.) TIA.

I cannot sign into Vanguard Mutual funds after 20 years of doing so. I can sign in using EDGE. I have the latest version of Firefox. I have some Ghostery stuff. I have Windows 11.

Anyone encounter the same problem?

To sync a mobile device, the instructions say to open Firefox browser on mobile, from Menu go to Sign In, aim phone camera at QR code. The 3 lines at the screen bottom right (i'm assuming this is a menu but printing an icon labelled "menu" is less cryptic) offers no sign in opportunity.

Just bought my new Acer Lap Top Downloaded Firefox on it. Trying to bookmark some of my sites. It first let me bookmark them. Now they have all disappeared and it will no longer let me bookmark anything. Can anyone please help me?

As of 12/9/25, Firefox seems to now prevent Theme add-ons from working if there is a contrast setting configured in Windows configuration. (Version 146.0) Previously, this allowed a very aesthetically pleasing view. I would greatly enjoy having that option again. Thank you.

Good Morning, Please how can I add or take out in firefox the icon shortcuts with most visited sites that I use, Also firefox is adding by itself shortcuts to my opening page and I don't want to have more than 6 or 7 or firefox suggestions. Thank you for your help

I have an account that I am not aware of having requested. The address is the same as the original account and the inbox appears to also be the same. It does state POP3 after the address. I want to remove this account. How can I do that?

When I tried to delete the account all the emails before today on the POP3 address and the original address disappeared. Is it possible to get the emails back or the recent ones?

Crash submitted, ID = 320cc808-4505-4cba-6e0f-9f2c2955d007 Still happens in troubleshoot mode. Still happens with extensions disabled (Ublock origin, Proton Pass) Started happening since Dec. 5, 2025 System is current with all Debian?Ubuntu updates installed (daily refreshes) Linux Kernel 6.8 on Lenovo Yoga i7 (ca. 2022) with Intel i5 & Intel graphics

The subject says it all. The "tabs from other devices" are a) Shown as a long flat list of links, not in their individual tabs, which is disappointing b) right click does nothing - doesn't open them as advertised

cannot access primary email. idiot firefox requires primary email in order to make backup primary !!!!!!!

Unbelievably poor design.

I have a backup email address, recover codes, phone.

but firefox requires the inaccessible primary email address to make any changes !!!!!@!@!@!!!!!

Hello. The browser will start fine and run for most of the day. I haven't made any known changes to the PC. At some point the browser will crash for all tabs and all windows. Any attempt to refresh goes to the screen as seen in the attached image. The "Restore This Tab" button does not work. I have to close all Firefox windows. Then the browser will work again.

I'm using an Alien computer. Windows 11. Everything is up to date. Firefox version 145.0.2 (64-bit)

Thank you.

I want to switch back from the Thunderbird Release channel to the ESR channel but I do not understand the steps. Please help me with the exact, easiest steps. I am running Win 11.

I am a big fan of firefox but i see some difference between firefox and chromium based browser that is Smoothness. All those scroll and swipe are beautifully smooth on Chromium based browser but in Firefox, it stutter and feeling visual lag. I know that Firefox is made by different engine but on IOS it's feels smooth but on Android it's sluggish. I hope you guys find a way to fix those problem.

Device: Redmi Turbo 4 pro Storage : 12/256 GB

Hello,

I just had Firefox overwrote a session restore I had open for a long time with a few hundred tabs. Is there any way to see prior session history or backup these sessions without manually copying the files? If not will these features ever be added?

Thanks

I use the email address maszyn1_laptop@interia.pl. The account is configured in Thunderbird on a Lenovo laptop. The laptop is protected by ESET Smart Security antivirus software. As recommended by Eset, I added ESET VPN to my protection. After enabling ESET VPN, the address doesn't configure. It requests a password. I receive messages that the server is disconnecting. Other addresses work. Disabling ESET VPN causes the address to work. This problem doesn't occur on my other Outlook email client. I would appreciate your help in resolving this issue. Sincerely, Paweł Jędrzejewski