Thunderbird Community Forum

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

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.

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

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.

When trying to open Thunderbird it does nt with the message "Thunderbird Not Responding" I try to open in Troubleshoot mode but that does not wotk either. I have to start and re start the laptop and finally after many tries it finally opens. Frustrating

After a reboot and Windows 11 update today, Thunderbird (I believe it was v155) will not open. It asks for the password, then sits at [Not Responding].

I have copied my profiles (there are two, one dated 2023 with only a 1K .json file in it, and one created tonight while I was troubleshooting that's several GB and when copying, appears to contain all my mail folders although I can't access them directly from within the profile) to a separate location (my desktop).

I've tried the following (after checking previous questions here in Mozilla support):

(1) booting Windows into safe mode

(2) opening Thunderbird in Troubleshooting mode (Shift while opening), both in Windows safe mode and normal boot

(3) uninstalled Thunderbird from Control Panel, downloaded and installed a new copy of Thunderbird

All give the same result: "not responding", can't click anything. Can only wait or close.

I was able to disable an extension that I installed yesterday that had been working fine.

I'm also wondering if the problem is mail folders that are too large. I have some candidates for deletion but since I can't see any .msf files for them, I can't delete (because I can't open Thunderbird.

I'm leery of instructions to outright delete any Thunderbird folders/files because (1) I can't see my mail folders directly and (2) I'm self-employed and all my client and business emails are in there. Losing them woud be a disaster.

I'm tempted to try the Windows option of restoring my entire computer to an earlier point, say, this morning. But that seems like possible overkill if it's an issue with just Thunderbird.

I'm freaking out, please help!

Mozilla Thunderbird stopped responding, tried to shut down, restart, uninstall and install - nothing helps Still opens the window, but no messages white backgoround and (Not Responding)

I added a new entry in my Address Book and sent a message to that person. I next tried to use Thunderbird to read messages and it locked up. No system shutdown/restart fixed that. Reinstall ofThunderbird did not fix it either. I have many stored messages that I do not want to lose, so I have not erased all about Thunderbird. What do I try next?

I cannot open the email program with Thunderbird, I have trie to open it by pressing Shift and Thunderbird Icaon, thus the Repair menu opens, I have tried every combination in that , like starting in the secured modus, but it did not help, I have tried to delete the "parent-lock" data in %appadat%\Thunderbird\Profiles\ - it said that I cannot delete it,because it is opened in Thunderbird. Would you kindly help me? Thank you very much

When starting thunderbird, the program cannot find my e-mails and does not respond. It is frozen. deinstallation and new installation did not help. The version i do not know because I cannot open the menue.

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?