I-Thunderbird Community Forum

Today TB froze during start up. No problems yesterday.

I deleted global-messages-db.sqlite and restarted TB. Now it is frozen with a "Loading messages". Maybe it is rebuilding indexes and this takes a long time and I should be patient.

Maybe my In and Sent mail boxes are too big? If so, how can I safely prune them?

TB is becoming increasingly unstable for me. It was very reliable before about a month ago.

I doubt my AV is the culprit because AV has not changed today.

Thank you one and all.

Greetings,

I've lost the ability to receive e-mail, Suddenly Thunderbird just quits on me with no warning. Apparently I can still send mail but cannot receive. This is the second time this has happened to me in as many months. How do I fix it? How do I prevent it?

Thanx

Was kann ich tun? Habe Probleme mit mozilla. Bei derAuführung der Programme Thunderbird ( ständig ) und Firefox ( manchmal ) kommt es zu Abstürzen wie Programm keine Rückmeldung, einfrieren so das keine Eingaben mehr möglich sind und ich jedesmal das Programm schließen und neu starten muß.

Additional details:

• Operating system: Windows (please specify your Windows version if known)
• The issue started on August 25, 2026.
• Thunderbird becomes unresponsive shortly after startup.
• A “System Integration” prompt appears before Thunderbird becomes unresponsive.
• I cannot click any buttons once Thunderbird becomes unresponsive.
• I tested both available profiles (“default” and “default-esr”) using the Profile Manager, but the same issue occurred with both profiles.
• I also started Thunderbird in Troubleshoot Mode with all add-ons disabled, but the issue still occurred.
• I can force-close Thunderbird through Windows when it becomes unresponsive.
• I have not deleted or modified any Thunderbird profile files because I want to avoid losing existing email data.
• The profile containing my email data appears to be “default-esr”.

I would appreciate any guidance on how to identify the cause of this issue and restore Thunderbird without losing my existing emails.

When I try to start Thunderbird on my Windows 11 laptop it does not start properly It is haging ond after a whike i get a message that thunderbird does not respond ("svarar inte" in swedish). Sometimes if I try to reinstall Thunderbird it starts up, But today nothing happens.

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!

win11 :Thunderbird will not launch, It appears the issue is a Background Process labelled "Thunderbird" which is unresponsive to "end task" in Task Manager. Will launch after reboot.

I have no clue as to how Tbird into this state, but it has happened more than once

Thunderbird Version 156.0.1 Build ID 2026092215180

For about 2 weeks, EVERY time I try to write an email, after typing a few lines or so, the whole window 'grays out' and becomes UN-responsive. I get no error message. Waiting for it to respond doesn't work and I have to close out and re-start Thunderbird. Sometimes Thunderbird will have saved some portion of my email in my 'Drafts' folder, but not reliably, so I have to frequently 'Control + S' - save it to avoid having to re-type the entire message again. Troubleshoot Mode doesn't help, nor does clearing the cache. I've been hoping an update would come up that would solve this, either from Thunderbird or Windows (11), but not so far. Please tell me how I should resolve this - I have used Thunderbird for years (and regularly contribute too) and don't want to have to change to different email client.

Upgraded from Windows 10 to 11 a couple months ago. Since then, TB freezes nearly every time I am composing an email. "Help About" says TB is up to date. Remedies? Or do I have to wait for a new version?

Chris Sackett

Hi all, I'm experiencing persistent and reproducible segmentation fault crashes with both Thunderbird (versions 140.0.1, 141, and 142 tested) and Betterbird on Arch Linux. The crashes occur consistently within 30 seconds to 2 minutes of operation, making the application unusable.

System Configuration:

• Arch Linux (fully updated)
• KDE Plasma 6 on Wayland
• Multi-monitor setup using DisplayLink/evdi drivers
• Firefox works perfectly fine (no crashes)

What I've Already Tried:

• Fresh profiles (completely clean - crashes persist)
• Safe mode with add-ons disabled
• Disabling hardware acceleration (MOZ_DISABLE_RDD_SANDBOX=1, --disable-gpu)
• Software rendering mode
• Multiple Thunderbird versions (140, 141, 142)
• Alternative client (Betterbird) - same crashes
• Full system upgrade

All crashes show the same signature in libxul.so during startup/operation. The stack traces consistently point to Mozilla's threading/compositor code. Notably, Firefox using the same libxul.so library works without any issues, which suggests this is Thunderbird-specific.

I believe the issue is related to KWin compositor interaction with my multi-monitor DisplayLink (evdi) setup on Wayland. The crashes are specific to Thunderbird/Betterbird and do not occur with Firefox, despite them sharing core libraries. Note that this problem happens on both x11 and Wayland.

I have extensive coredumpctl output available if that would be helpful for debugging. Has anyone else experienced similar crashes with multi-monitor setups or KWin/Wayland compositor issues?

Any assistance would be greatly appreciated!

Abbreviations ( Nat'l for National) locks up a send function. A mis-spelled word locks up TBird when I click send. For either instance the mouse will not click on anything except the red X delete.

In the last week or so, Thunderbird has become unreliable about opening - sometimes it opens with no problems, sometimes not. Sometimes closing the VPN appears to solve the problem, other times not. Sometimes opening the VPN appears to solve the problem.

Overall, I'm looking for a new email client after years of using Thunderbird.