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Since 3rd September 2026 Thunderbird opens a system integration window and then goes to not responding. I cannot access my emails through this software at all at the moment as there's no way past his pop up. Version 153.1.1, Windows 11 Home.

I wanted to share a specific startup freeze loop I encountered today.

I had a moderate number of tabs open in Thunderbird when I quit the app. I had set up a single IMAP message filter yesterday to automatically move incoming automated text alerts into their own folder (causing about 50–60 small emails arriving in quick succession this morning at startup).

The Problem: Upon starting up, the app almost immediately choked and became unresponsive. Unlike the freeze report by another user here on August 21st.

My Workaround: After a few attempts to open Thunderbird I managed to break the freeze loop by instantly closing the single open UI window right at startup. This kept T-bird running invisibly in the macOS background. It seemed that without the need of rendering the UI, the background engine successfully completed all the IMAP syncing and filtering tasks.

When I brought Thunderbird back to the foreground, all my open tabs instantly "snapped", and the app has been perfectly stable since. I haven't tried to replicate this due to the fear of breaking the current stability.

Has anyone else recently noticed Thunderbird freezing under similar conditions lately? Let us know if this workaround helps you get past your startup freezes too!

I have been using Thunderbird for years with no problems. However recently, Thunderbird very often simply stops responding. Sometimes it just hangs up and sometimes the program bar at the top displays "Mozilla Thunderbird (Not Responding)". If I try to wait for it to respond, it literally hangs for several minutes before it begins to respond again, and often, it simply never starts responding again. It has simply gotten to the point where Thunderbird is practically unusable. All my other application software continues to work with no problems. It's just Thumderbird.

The version number in this submission may not be correct. I can't provide the real version number because of the hangups.

Any suggestions?

I have used Firefox since version 1.5 and have loved it and the community since. However, since finally scrapping Windows and switching completely to linux, Firefox has been frequently troublesome with random crashes. The crashes occur on any website I may be on and for seemingly no reason. It happens when I'm in the middle of browsing a page, just opened a new tab, or even when Firefox is simply open and I'm active on another open application.

Environment is as follows:

OS: Zorin OS 18 (Latest patches) (Based on Ubuntu) Mobo: Asus Crosshair VI Hero (Latest available BIOS) CPU: Ryzen 9 5900XT GPU: EVGA GeForce RTX 3080 XC Gaming (10GB) Ram: 8GBx4 G.Skill TridentZ RGB DDR4 (3200) Sys Drive: Samsung 970Evo M.2 Nvme 500GB

Firefox is installed via Flatpack through the built in app store in Zorin OS.

The crashes will sometimes be constant as well. Such as when it crashes, crash reporter comes up, then I click "Restart Firefox" and the second I see the window, it crashes again. This has been a constant problem though at random times ever since I switched back to Linux about 5 months ago.

Any help would be greatly appreciated. I don't want to have to change my primary browser from one that I am generally so happy with, and is also the browser that I recommend to everyone.

Dozens of reboots every day due to video seizures only with Firefox. Tab crashes causes those I am ordered to support to LOSE WORK. After a tab crash and restore the FF interface is frozen -- no type of input from peripherals possible. This is all supposed to be solved by Monday. If I am out of luck with FF -- just tell me. That's very simple. New machines, new OS and it's worse than under the legacy systems we support after moving up from Win 7 Pro.

I think it started to happen with Version 128.9.0esr | Released April 1, 2025. It is very simple to reproduce: 1. Start TB. 2. TB downloads new messages and continues to do it every 1 minute according to the setting. 3. In 10 to 20 minutes, it hangs. I have to force it to close and then restart it to check my email.

I believe it started to happen yesterday.

Is anyone else experiencing this?

Hello! I used Thunderbird on a MacBook Pro with MacOS Catalina 10.15.7. No problems for years up to version 139.x. Now, starting with version 140.x, high CPU load and crash when exiting the Thunderbird. App Error also occurs with a completely new MacOS 10.15.7. Installation only with Thunderbird 141.0 and empty profile.

Does anyone have any tips?

I would like to continue using Thunderbird without any changes.

Best regards, Robert, Austria.

Firefox crashes whenever my computer goes to sleep. I am running windows 11 and have been for years. This problem showed up a few months ago. The crash then screws up other apps and I have to restart my computer to fix it.

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!

Suddenly Thunderbird takes a long time to download even a few (10-20) emails from Gmail and then it freezes on an email and as I click on different emails only the original one shows on the bottom half of the screen, even if I change to a different folder/email account. Also it will not close when I hit the X in the upper right corner.

If I click on one of the other apps, such as Calendar it goes to calendar but when I go back to email it still shows that same frozen email.

I tried clicking on the three bars (hamburger) to find the Thunderbird version and nothing happens.

I have restarted the computer but that has not helped.

This is an add on to the previous portion that I wrote yesterday. Today nothing shows in the portion where I usually view the message after I've clicked on it. Also the options in the tool bar such as File, Edit, View etc. do not respond to a click after the first time I have attempted to look at a message.

I am considering uninstalling and reinstalling. If I do that will it find all my emails and folders etc. again? There are a few emails that I am quite desperate to access that I have put in folders.

I'd really appreciate any help I can get on this as some important work is being delayed until I can access those emails.

Thanks for any assistance!

I'm able to add an e-mail account but when I go to add a second e-mail account, when it looks up the information, it just hangs with the circle going around.

This is true for two different user accounts on the same computer.

I've uninstalled and reinstalled Thunderbird but it didn't help.

Thunderbird can't be exited without killing from the task manager or shutting down.

1. Whenever I open Firefox for the first time since boot, it crashes, and I have to click on it a second time for a window to actually show up. Once it shows up, it's forgotten all about the previous session - none of my tabs re-open, the window opens up maximized.

2. Whenever I close the last open window, my previous tabs are completely forgotten. Checking task manager reveals that there are 10 or 11 Firefox processes that are still running.

• I have a second Windows 11 device that DOESN'T exhibit any of these issues and works correctly. Closing Firefox does not leave any running processes around.
• "Open previous windows and tabs" is enabled in options.
• "Firefox will: Remember history" is set in the History options.
• Both devices are running Firefox 137.0.2 64 bit.

Problematic PC specs: Edition Windows 11 Pro Version 24H2 Installed on 3/23/2025 OS build 26100.3476 <<< This is different! Experience Windows Feature Experience Pack 1000.26100.54.0 <<< This is different!

Working PC specs: Edition Windows 11 Pro Version 24H2 Installed on 3/4/2025 OS build 26100.3194 Experience Windows Feature Experience Pack 1000.26100.48.0

Hi -- I'm getting quite a few page crashes that seem mostly tied to YouTube, although not exclusively. I only recently swapped over to Firefox from Chrome because I was having similar crashing issues with that browser as well. This is after a fresh install of Windows 11 Pro and a number of different benchmark tests (no known issues with CPU, GPU, or RAM).

Since there are so many reports that all seem different, could someone help troubleshoot? I really can't tell if it's a browser problem, maybe something with my MOBO or PSU or other hardware.

bp-8849827b-dbff-4f56-ab32-a00e50251111 11/10/2025, 7:04 PM bp-b9b83d66-9ac5-4eae-9676-367000251111 11/10/2025, 7:04 PM bp-4b8e92c0-0a15-45ef-b8e1-567920251111 11/10/2025, 7:02 PM bp-4c1a61f1-674e-4da0-8921-156f50251110 11/10/2025, 12:21 PM bp-659dc04a-4933-4a3b-919b-3c1c50251110 11/10/2025, 12:21 PM bp-9387464a-bc4e-4217-995a-f457f0251110 11/10/2025, 12:21 PM bp-97bc77f5-3fa3-4623-b48b-d94e90251110 11/10/2025, 12:21 PM bp-47d723e7-4eab-41d1-b97b-410ef0251110 11/10/2025, 12:21 PM bp-58abdc4e-d959-41c9-bf0a-469280251110 11/10/2025, 12:21 PM bp-b593054f-5a6c-4693-82c8-79d410251109 11/9/2025, 6:47 PM bp-13f555f8-c219-4995-b09f-b15440251109 11/9/2025, 2:11 PM bp-91cbf8ab-d793-4781-ba28-0fd030251109 11/9/2025, 2:11 PM bp-5e7db47b-6114-4cc6-a1ac-daaca0251109 11/9/2025, 2:11 PM bp-ef240795-bedf-4c26-91f2-386ba0251109 11/9/2025, 2:11 PM bp-51ec26ab-03f0-4e0b-b199-b2f600251109 11/9/2025, 2:11 PM bp-aef18aaf-1b2e-410e-9170-99fd50251109 11/9/2025, 2:11 PM bp-e5bc73e3-293e-4b3a-8974-e088c0251107 11/7/2025, 1:38 PM bp-85a1ba73-0df8-484b-b9bb-945cc0251107 11/7/2025, 10:59 AM bp-26c84615-670b-49e8-88aa-c26ac0251107 11/7/2025, 10:59

Thunderbird has pretty much disappeared from my iMac, and I cannot find a way to solve this problem. I've restarted Thurnderbird multiple times and restarted the iMac. It came out of nowhere, and I do not know what to do. I've attached a screenshot with the screen that pops up when I open Thunderbird. None of the dropdown menus work, and I cannot access my years of email. Help!

I believe this started with this upgrade to the client. I routinely was able to select a piece of text in an email and click the Insert Link... button, fill in the data, and click OK to embed a link.

Now I select a piece of text, press the Insert Link button, and Thunderbird hangs, requiring Task Manager to kill the program.

Embedded links already in i.e. templates work fine, but cannot be edited or upgraded.

Anybody else seeing this, or am I (typically) just being stupid about something?

Thanks John

I’ve observed a consistent issue across several Android devices using Firefox (latest stable version). When trying to launch or interact with certain modded APK-based games—especially those with unpacked resources or modified DEX structures—Firefox either freezes or crashes unexpectedly.

Interestingly, this behavior doesn’t occur on other browsers like Chrome or Samsung Internet. In fact, some third-party websites seem to handle these APKs with stable performance, suggesting it's not an issue with the APKs themselves but possibly how Firefox handles local server callbacks, file-based intents, or memory allocation under WebView.

I’m wondering if this could be tied to Firefox’s stricter security sandboxing, CSP enforcement, or service worker management?

Are there any logs, flags, or debugging routes I can use to isolate the problem further?