Forum der Gemeinschaft Thunderbird

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.

I received a message with a password-protected attachment, and opened it in Thunderbird (in Windows 11).

I found that the password I'd been sent did not work with the attachment. I inadvertently closed the Thunderbird app with the password prompt still open.

When I tried to open Thunderbird again it tried to load the attachment and then just hangs indefinitely. Using safe mode has the same result.

Please can you suggest a solution?

Thanks

Even when it opens correctly a message appears:

The certificate for mail.capsense.com is not valid for that server. Someone could be trying to impersonate the server.and you should not contijnue.

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

I have down loaded the latest version of Thunder Bird. The program still has my settings to access my e-mail. For some reason every time I try and read my e-mail the program locks up and I have to do a Task Manager to stop the program Any and all comments would be appreciated. Thanks Dave

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