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In recent weeks, Thunderbird often hangs when I'm replying to another email and have written a sentence or two. It never recovers, and I have to close the program from Windows.

It doesn't always do this. On a few occasions, if I wait a while, close Thunderbird from Windows, and restart it, the partial is in the Drafts folder.

I'm running Windows 11 24H2, but I've been on 24H2 since December, and this problem is more recent.

Hello, I hope this message reaches you. I have a Mac operating on OS 10.15 .7. Ever since I upgraded my Thunderbird to the 141.0 version, two things happen: 1) the fans of my Mac start ventilating very soon (and the battery starts going down) 2) when I quit Thunderbird , everything goes back to normal , but 10 seconds after, a window opens reporting an unexpected shut down. I usually click OK , but when I click "report" , nothing happens. Thanks for your help J.C.

Hello, Here is what I consider a new bug in TB. It goes this way: While I am reading a message in the message pane of the standard window (not in its own window), if messages arrive (with a small ding for me), the message pane I am reading goes BLANK and the message I was reading is deselected. I have to reselect the message I am reading and scroll down to where I was. This behavior is very annoying and did not exists in previous versions.

I hope this helps. Thank you , Alain Damlamian

Confused. Version 144.0.1 | Released October 16, 2025 Says 32 bit. I thought I downloaded 64 bit.

Problem: Freezes when I click anywhere on TBird desktop

How do I address the freezing problem?

Thanks Robert

MAC OS Tahoe 26.0 Public Beta 6 Since upgrading to this latest beta, with Open NewMassage in a new message window, does not open the window. It seems to create it in the back ground, and Thunderbird icon on the task bar shows the additional windows, but they are un selectable. Choosing open message in newt does work.

This seems to be occurring after beta 6 , it was working under beta 5

I've used Slack every day for the past decade, and Firefox has been my primary browser for some time now. I've never had an issue with the two, but now, Firefox is reliably crashing every time I attempt to open Slack.

I've tried clearing my cache both broadly and specific to Slack, with neither producing results. Even tried deleting all cookies on Firefox, which was a bit of a pain, and it was no help.

I did read up on some people encountering a similar issue that could be fixed by deleting the Slack entry in "about:serviceworkers," but this did not help here.

The only extension I'm running is uBlock Origin, which I've been running for probably as long as I've been using Firefox, and that has never presented an issue before either.

Would appreciate any help or advice on the matter.

I have Win 11 dell computer that does not play or pick up sound from web sites videos .I checked and tested my sound using the Microsoft platform & buy playing a disc. It works OK

Started using Netscape and been with Firefox ever since it started. For the last few months, I find that my Draytek 2866Lac router randomly crashes and resets itself when I am using Firefox. I cannot pin it down to opening any particular website but it seems to be related to opening a new tab / link. I have FF set to open new tab automatically and no extensions (other than British English) are in use. Using FF, I can seldom go more than 5 -6 hours between resets. Not using FF, I have now managed 2 days constant uptime on the router - which is a fantastic change! Is there something peculiar with my system and any ideas how I can get stability again please?

URGENT Version 142 for Windows 64bit is unstable. It freezes over after almost any action with usual Windows "Not Responding" message. Recommendation to Mozilla: Pull back this release and roll back to 141

Trying to download updates from Intel.com and as soon as I click the download button, Firefox just locks up and won't allow me to do anything. I have to basically shut down firfox through task manager to get the browser to work again. I have 139.04 which is the latest update for Firefox

A message to Mozilla if this is a bug how about fixing the problems that some people are having instead of consintration on implementing AI into Firefox as I want a browser that doesn't and isn't link to AI as many other people do as well as some if not most of us are sick to ther back teeth with everything having AI installed with in the programs.

I'm using Win 11 and ver 140.3.1esr (64 bit)

Thunderbird works perfectly except for just one thing. Every time I write any email it freezes after about 2 minutes. If it's a short email, it gets sent. If it's longer, before I can get to the end, the program freezes, and I have to use Task Manager to stop it. No problem receiving and reading emails. This started about a month ago.

I use Bitdefender, but it still happens with that off. Windows is up to date. Any ideas why this is happening? Thanks.

Hi I have just reloaded Thunderbird onto my laptop after installing a new hard drive. It worked Ok until i imported an account and now get this error message even if I uninstall and reinstall.

That appears in a box and thats it.

Cheers Jim

When I attempt to add an attachment, sometimes Mozilla crashes. This happens several times a month. Windows 10 Home "File Explorer" pops up & I can be scrolling and it will crash Mozilla. Other times I am selecting the file to attach & it crashes. I am at a loss as to why. I'm using the latest version & "Send later" is my only add-on.

On my Framework 13, Thunderbird has stopped. Message reads Oups! We're sorry, it looks like thunderbird crashed. Please contact the developer if you want to report the issue. At 85, I'm anything but a nerd. Could someone please help me in simple, everyday terms? I have a lot of incoming and outgoing emails, and am completely stuck. Thank you.

Submitted Crash Reports Report ID Date Submitted bp-28e075fd-226a-4a7c-bbeb-4066f0250119 19/01/2025, 12:16 pm View bp-ddcd262a-6efe-49db-b2fd-db21f0250119 19/01/2025, 12:16 pm View this happens at the most annoying time, I have submitted the crash reports as advised.

Thunderbird pushed out an automatic update last night (July 13 2025) to version 140.0.1esr. Since then I cannot complete creating and typing a new message without Thunderbird freezing completely during entry of the text of a new message. I am running Windows-11 home, version 24h2. I have rebooted, etc. multiple times. I also ran thunderbird in troubleshooting mode and the problem still exists.

Please help - as of today Thunderbird is completely useless to me.

wellerhn@gmail.com

Thunderbird has worked fine for me for years on my Windows 10 Pro machine. The computer works perfectly otherwise--and has a large amount of RAM. But a few weeks ago, Thunderbird started freezing (stops responding) at some point while I'm writing a message.

What happens is that I'll start to write an e-mail message in Thunderbird, and at some random point (from a few seconds to a few minutes) it will stop adding what I'm typing, and soon the text that it was showing grays out. It will then say Thunderbird has stopped responding, and I have no other choice than to close Thunderbird. I have no way of saving or recovering the message I had been typing--very frustrating!

As a partial work-around, I found that if I click on "Save" every time I add a little more to the message I'm trying to write, then at least when I restart Thunderbird I can go to Drafts and recover the message (as it was the last time I clicked "Save").

Thunderbird still works fine for all other functions (reading received messages, etc.). It only has the stopping responding problem randomly when I'm trying to write a message. It can happen while I'm typing--or during a pause between writing sentences. And the timing of the problem is very random and variable (from almost immediate to a few minutes). I tried running Thunderbird in Safe mode, but the problem was the same...

I always keep up with Thunderbird updates. Currently, I'm using version 140.1.1esr.

Can you give me any help with a solution? This problem is maddening!

Thank you,

Vincent Andrunas

For about the last year when I try to open Mozilla Thunderbird calendar, instead of taking me to the active calendar page, I get a “Not Responding” message and an hourglass for about 1 minute. That eventually disappears. I then have to select “Calendar” and wait another minute or so with another “Not Responding” message before I can finally get to the active calendar page and do what I wish to do on the calendar. When I remove the app and reinstall it, the problem disappears once ONLY and reappears after that. Can you suggest a solution to the problem, please. I have a Dell Inspiron 3793 laptop.

Thank you.

EDL