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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.

Thunderbird doesn't open. I suspect because it opens every message I get or send either in a tab or a list or both. Then there gets to be too many of these. I didn't ask for any of these things! Why can't I just get messages like I used to, and not have to constantly be concerned with closing tabs and closing lists? It is ridiculous, and now the program won't even open. I know I am asked to be polite, and it is the programmers who are at fault, not the community volunteers. But we are not allowed to contact and complain to the programmers!

Sorry! 0 results found for ‘Thunderbird locks up when I'm typing an email and says Thunderbird is not responding. Has been going on for a couple of weeks. I'm on Windows 11.’ for ‘Thunderbird’

Thunderbird is freezing when I try to type a message into the new message window. It takes maybe 100 characters or so, then just freezes and requires ctrl-alt-del and end task to get out of it. This began with auto-installation of 140.0.1 as described below, and is 100% reproducible.

Environment: Windows 11 home 64 bit (specifically 2025-07 Cumulative Update for Windows 11 Version 24H2 for x64-based Systems )

Running Thunderbird 140.0.1: Thunderbird 140.1.1esr was auto installed on July 10, 2025. Version history says that the install failed, but version showed as 140.0.1esr. This is when the problem began. On July 18th, I downloaded the release version of Thunderbird and installed that (140.0.1 - no esr). This did not resolve the problem. Troubleshooting info now shows 140.0.1 - no esr as the current version, but the update history does not show that upgrade/downgrade in the list, so I'm not sure it happened.

Things I have tried: Windows safe mode Thunderbird safe mode Clear caches Removed several mail accounts from Thunderbird

Below is system info from Thunderbird troubleshooting page.

 Application Basics

   Name: Thunderbird
   Version: 140.0.1
   Build ID: 20250709044702
   Distribution ID:

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.

Why for about the last week has Thunderbird been crashing when drafting a message? Often it saves a portion of the in-progress drafting, but not always. What is the fix?

This is an issue that cropped up with the last update to T-bird. It retrieves and displays emails as well as it always has, but now when composing an email reply, T-bird completely locks up, can't shut it down by any means other than using Task Manager and killing the process. Before killing it, though I expanded T-bird's processes, and it listed five instances, one of which read "Not responding." When this happens, the cooling fan in the laptop kicks into high gear, until shortly after I kill T-bird.

Needless to say, this is intensely annoying and inconvenient. I belong to an extremely busy recovery group, and email is my primary contact with them, so this makes things a royal pain. I've had to resort to hitting "Respond" to open a new email, then firing up the text editor to compose the reply, then cut/paste that in and send it. Workable, but really... it *was* working fine, and now it isn't, and I haven't changed a thing, Windows hasn't updated, no new apps or anything... it just stopped working.

I've tried a number of suggested fixes, such as removing all add-ons (removed, not disabled) and themes, creating a new account (which worked okay for about a week, then it too started locking up). About the only thing I haven't tried yet is uninstalling T-bird and re-installing it, which I'll do if I absolutely have to, but I'd rather not go through the hassle of rebuilding everything if there's any other way to fix this.

Is there any kind of information or file/s I can provide that someone may be able to make some sense of? I'd REALLY appreciate it. I've used T-bird since I had internet access (back when Alta Vista was still a thing), and I love it - - no other email app offers the breadth of features that T-bird does, even paid apps. I'd truly HATE to have to switch to something else over this!!

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

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, 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

When I try to add a new Mail Account, the "Looking up configuration" step hangs indefinitely. I have to force a hard exit to reopen the app. I was able to add my hotmail account without issue, but now that I'm trying to add @yahoo.co.uk , it just freezes up. Thx

Windows 10, newest Thunderbird.

The computer has rebooted from a bugcheck. The bugcheck was: 0x0000000a (0x0000000000000030, 0x0000000000000002, 0x0000000000000000, 0xfffff80274225392) CAUSE WAS FIREFOX.EXE

The computer has rebooted from a bugcheck. The bugcheck was: 0x0000000a (0x0000000000000030, 0x0000000000000002, 0x0000000000000000, 0xfffff80274225392) CAUSE WAS FIREFOX.EXE

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.

Since a few days, Firefox started crashing each time I receive a notification.

For example, with this notifications test website: https://www.bennish.net/web-notifications.html

Each time I click on the "Show" button to display a notification, Firefox becomes completely unresponsive: the content of the window is completely frozen and I can't click on anything. I must close it and restart it to make it work again. When I restart it, a dialog displays:

> Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window.

In both applications, the notification is never shown: the freeze occurs before.

I tried the following changes but they did not stop the issue from occuring:

- Deactivating hardware acceleration - Troubleshooting mode - Deactivating firefox notifications in Windows - Deactivating `alerts.useSystemBackend` and `alerts.useSystemBackend.windows.notificationserver.enabled` in `about:config`

At the same time, I noticed that Thunderbird (v144.0.1, 64bits) started having the same issue. It haappens each time I receive a new message in the background and a notification should appear. Maybe this is related?

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

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

Just over a week ago, I found that a particular page transition always crashed by browser tab (i.e. a reproducible crash). This occurred on the Quora.com website when visiting the 'Questions' tab for any Quora Space. I am not aware of anything special associated with this operation, and it works OK in Chrome. There may be other cases -- outside of that particular website -- but that is the one most affecting me at the moment.

There are no associated Windows events logged. I checked about:crashes and the Crash Report folder but i cannot find any readable details.

If I refresh the page then the transition occurs without problem.

I would like to find the cause myself because I am on an Windows 7 64-bit ESR version, although I do not believe this is an ESR issue as it was working fine a couple of weeks ago. it is just that I cannot find any logged information on the cause.

WHY CAN'T YOU FIX YOUR BUGGY BROWSERS??? LOOKS LIKE I'M GOING TO OPERA OR EDGE NOW!!! STOP C0000005 ERRORS! I CAN'T BELIEVE HOW YOU'VE MESSED UP A ONCE-GOOD BROWSER!

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