థండర్బర్డ్ Community Forum

I have an extension that I depend on and it is not compatible with the current version of Thunderbird so I need to backup until it starts working again. How can I download earlier version of Thunderbird?

Thunderbird 143.0.1

My TBird updated this morning and everything turned to crap...

I have TBird set to check for emails every 15 minutes on 4 accounts. There are also 3 accounts that I monitor and check manually...

As soon as the 143.0.1 update touched home base TBird went ballistic. Withing in seconds of it checking for mail on the four accounts it then started deleting the accounts. Any mail was down loaded then poof!! No mail and No mail account. I had to crash dive my laptop to to stop it. Spent 3 hours trying to recover the emails and accounts and managed to reclaim 3 accounts out of the 4 but lost all the emails... After all that effort I was totally peeved and decided to uninstall TBird and revert to an older version... The icing on the cake TBird wont unistall because the YES button on the TBird Helper window wont activate...

After more than thirty years of supporting Firefox and Thunderbird... You have really dropped the ball with this one... As far as me getting an email when someone answers the thread... Good Luck...

Old PC is Dell WIN 10. New PC is Dell Win 11.

Is there a way to move the entire program from the old PC to my new WIN without having to re-install

Please advise. I don't want to start from scratch.

I have been using Thunderbird successfully on Windows for years now, as my email client for a PlusNet email account in the UK. In May 2026 Thunderbird suddenly disappeared, as if it had been uninstalled, but I have no idea why. I managed to reinstall it and rediscovered the server details needed to reconnect to my account and fortunately had a slightly old back up (from Nov 2025) of previously saved emails. This has worked OK now for about a month.

Today the same thing has happened again - The Thunderbird icon on my desktop does not connect to anything and has just turned into a white "blank page" icon.

I may be able to get the account back by doing the same tedious process again, but I am concerned that this may keep happening and I don't know why.

This is a work laptop running Windows 11 so its possible I suppose that some sort of security software may be doing this without notifying me?? I am using Thunderbird to access a personal (ie not work) email account so maybe my work systems don't like that? As mentioned, it has worked fine for years so I dont know where the problem lies but it is worrying and annoying.

PlusNet last year transferred all email accounts to another UK provider (Greenby) but that has worked OK and I cannot see how that would affect email client software.

BJ

I had to start anew with Firefox on my desktop. New password and settings. I am recognized, but i cannot find my e-mail to open

you say you will send an e-mail when someone has an answer for me .. i may get it on my mobile, but my desktop does not even have an e-mail account showing

Every time I try to open Thunderbird mail, I get a screen to install it again!!. Why is this.?? Is there a way to keep it installed.? Or must I jump through hoops each time I need to use email.?

Ever since last maj, windows are no longer resizable. Same Thunderbird version works OK on my laptop running Debian 12, but I cant easily upgrade version Debian 11 to debian 12 on this older desktop, so I wonder whether I could possibly de-install v140.13.0esr and re-install an older version, if then, which one would be suitable and available. If not, is there another trick to resize windows on v140.13.0esr ? Thanks in advance for your help.

I bought a new pc with windows 11 and everything is fine except that I installed thunderbird via microsoft store and when I gave it my email address, I could see my emails but it hasn't created a profile. Therefore when a try to view the profile it says user.../appdata/roaming/thunderbird/profiles... doesn't exist. I am logged on as an administrator. Should I uninstall then install from the mozilla website directly?

Recently I moved from a Thinkpad X1Yoga running Mint and Windows 10 to a Thinkpad P14s running Kubuntu and Windows 11 Pro 25H2. On the Win11 side (which behaves differently from Win10), there are installation issues affecting both Firefox and Thunderbird.

Win 11 Settings lists: under Apps > Installed apps

• . . . (other apps)
• Mozilla Firefox (x64 en-US) 154.0
• Mozilla Maintenance Service 153.0
• Mozilla Thunderbird (x64 en-US) 153.0.2
• . . . (other apps)

under Apps > Default apps

• . . . (other apps)
• Firefox
• Firefox
• . . . (other apps)

That is, Default apps lists Firefox twice (though not as "Mozilla Firefox"), but Thunderbird not at all. This causes two problems:

1. It's not clear which Firefox to choose for browser protocols.
2. There is no Thunderbird to choose for mail-related protocols,

Can someone tell me why the Installed apps and Default apps list differ, and how to set the appropriate defaults for Firefox and Thunderbird?

Thanks, John

Dell Desktop - Windows 10 to Lenovo Laptop Windows 11 I followed the Alternative Manual Transfer between Windows 10/11 Roaming Profile and Local Profile Now on Lenova - Mozilla will not open - Profile Missing - Your Thunderbird profile cannot be loaded. It may be missing or inaccessible. I do not know how to uninstall it or how to start over.

I am encountering a message of "The installation seems to be incomplete. Please check your hardware and disk setup and/or re-install." when trying to run Thunderbird.

This first occurred on a system that had been working for a while. An update may have been installed.

Here's what I've tried. -

Uninstall Thunderbird (along with Firefox and Mozilla Maintenance.) Checked for Program Files/Mozilla folder (all were removed). Run SFC / Scannow Run CHKDSK Installed pending Windows update. Restarted the System Renamed (essentially removed) Profiles folder Turned antivirus software off Downloaded and installed the latest version of Firefox, then Thunderbird. Launched Thunderbird. Still received the same error..

Any ideas on how to resolve the issue?

My Mac last night lost thunderbird (and numerous others things) and it's setting itself up again. I get an error that smpt already exists and I can't go any further! What's going on? Using Comcast Mail.

I am trying to evaluate your product, but i cannot load the program. it appears that this product does not have technical support. If the only technical support is from a forum or community, i will look at other products. i do not know the version since i cannot load it

I installed thunderbird for Windows on PC all was good till it went looking for a outgoing server a red box popped up and said outgoing server is already installed . That ended the install.