Thunderbird 社群討論區

Hello, I am experiencing repeated freezes in Thunderbird 153 ESR on Windows 10. I have been investigating this problem since mid-October 2026, but have not been able to identify the cause. Thunderbird is essential for my daily work, so I would appreciate advice on identifying the cause and restoring stable operation.

1. System environment - PC: dynabook R63/B - OS: Windows 10, 64-bit - Thunderbird: 153.6.0esr, 64-bit - Mail provider: @nifty (Japan) - Incoming mail: POP3 over SSL/TLS, port 995 - Security software: Super Security (Japanese security software) - Mail storage: Local mbox files

2. When the problem started Thunderbird worked reasonably well until September 2026. The freezing problem began around mid-October 2026. Windows Reliability Monitor recorded Thunderbird as "Stopped responding" on October 19, 2026, at 9:48 a.m. This is the earliest recorded incident I have found, although the problem may have started earlier. Thunderbird update history: - September 18: 153.3.1esr - October 1: 153.4.0esr - October 14: 153.5.0esr - October 21: 153.5.1esr - October 28: 153.6.0esr The first recorded freeze occurred after the update to 153.5.0esr. However, I have not established that the update caused the problem.

3. Symptoms Thunderbird becomes unresponsive and usually has to be forcibly terminated. During these freezes, Windows Task Manager often shows Thunderbird using approximately 30–40% CPU, repeatedly around 39–40%. Freezes also occur when Thunderbird is using only about 1.1 GB of memory. On other occasions, memory usage has increased to approximately 2.56 GB. The problem occurs under several different conditions: 1. During manual POP3 mail retrieval. 2. After repeated manual mail retrieval operations. 3. Approximately 30 minutes after a single mail retrieval, even when Thunderbird is left idle. 4. Sometimes after replying to messages or copying messages to other folders. 5. In both normal mode and Troubleshoot Mode. 6. Sometimes during the first mail retrieval after starting Thunderbird. Other Windows applications generally remain responsive when Thunderbird freezes. Restarting Windows sometimes restores normal Thunderbird operation temporarily, but the problem returns.

4. Troubleshooting already performed I have already tried the following: - Reinstalled Thunderbird from the official website. - Created a new Thunderbird test profile. - Disabled extensions. - Disabled hardware acceleration. - Disabled global search and indexing. - Removed all active Thunderbird message filters for testing. - Disabled the anti-spam component of Super Security. - Disabled automatic mail checking and automatic downloading. - Tested manual mail retrieval in Troubleshoot Mode. - Reduced the size of the Inbox from approximately 4.1 GB to 2.4 GB. - Performed a full antivirus scan, which detected no threats. The new profile initially worked, including several successful POP3 retrievals, but the freezing problem later returned. Reinstalling Thunderbird did not resolve the issue. The anti-spam component remains disabled for testing, but the problem continues.

5. Windows error records Windows Reliability Monitor recorded Thunderbird as unresponsive on October 19, 2026, at 9:48 a.m. Windows Event Viewer also recorded an Application Hang, Event ID 1002, on October 30, 2026, at approximately 4:23 a.m. The affected executable was thunderbird.exe, version 153.6.0.0. These records confirm the application hang but do not identify its underlying cause.

6. POP3 communication Earlier POP3 logging confirmed that Thunderbird connected to the @nifty POP3 server and received a CAPA response. However, I have not identified which POP3 or internal Thunderbird operation was active at the exact moment of the freeze. I have not collected a process memory dump.

7. Potentially related Mozilla bug reports I found two reports that may be relevant: - Bug 2080699: POP mail retrieval becomes unresponsive in Thunderbird 153.4.0esr. - Bug 2031744: Freezing potentially related to mail index (.msf) files and background processing. Some symptoms are similar, but I cannot determine whether they have the same underlying cause.

8. Questions I would appreciate advice on the following: 1. Are there known POP3-related freezes or high-CPU problems in Thunderbird 153 ESR, particularly after the October 2026 updates? 2. Could background mail processing, folder maintenance, or mail index files explain a freeze that occurs while Thunderbird is idle? 3. Could interaction with antivirus software or Windows networking components cause these symptoms? 4. Are there diagnostic steps that can help identify the cause without repeatedly freezing Thunderbird or risking existing mail data? 5. Would this information be more appropriate as an additional comment on an existing Bugzilla report or as a separate bug report? I have already spent considerable time testing different configurations. I would prefer to avoid repeating tests that have not helped. I have a backup of my Thunderbird profile and would like to preserve my existing mail data.

Thank you for your assistance.

I'm running 153.6.0esr on Windows 11. I recently signed up for Fastmail (using IMAP) and since adding that account, Thunderbird crashes ~90% of the times I open it - just perma hangs before it can ever show all my mailboxes. This is curious because I have a different IMAP account (different email provide) that has never caused this behavior. Starting in Troubleshoot Mode doesn't help.

I tried checking off "Check for new messages at startup" on that account, but whenever I try to load Thunderbird, I can see it stuck (in UI text at the bottom) checking Fastmail servers...

Occasionally I get lucky and Thunderbird does load ok, I can then use it ok. But even in that case when it can load, *sometimes* it loads my Address Book, but sometimes it thinks my Address Book is empty.

Fastmail would only advise me that I might have a corrupt Thunderbird profile. Fine, I guess I'll try making a new profile, but I have a few questions:

1.) What might have caused this corruption? Clearly it was something about adding a new Fastmail account (whether Fastmail specific or not). Is it possibly something to do with Address Book? Is there some other fix I should try?

2.) Even if a new profile works, how do people usually deal with importing other old accounts? I have a number of big old POP accounts and I need to have all that email around to reference. Do I just try copy and pasting those mailboxes into the new profile?

Thanks.

Since 2 day when I attach a document always unknown software aception (0xc0000417)on place Ox00000000501

NVIDIA Systemsteuerung nicht gefunden pops up I dont wont KI on my computer

I am sick & tired of Thunderbird email crashing. It has got so bad that I can only answer one message before it crashes again. It is useless at the moment. Help please.

Starting over the weekend, I have been unable to load my Thunderbird messages, it just says:

Home - Mozilla Thunderbird (Not Responding)

I wait, but it doesn't load.

Could I have too much stored in my email folders on my pc?

What can I do to get it to work again on my pc?

Online web browser works.

I cannot get Thunderbird to launch. It acts like it is stuck on perhaps one account and circles keep spinning as if it never can get a few of my tabbed emails open. It keeps saying it "isn't responding." Since this began happening a few days ago, I've stopped the Thunderbird task through Task Manager, I've shutdown and restarted my whole system multiple times, I've updated to the latest Windows platform and made sure my drivers were all up to date... I can't update my thunderbird (if required) because I can't get in in the first place. I have hundreds of emails in multiple accounts under my current Thunderbird. I can't afford to lose all that history. I don't know which version I'm using because, again, I can't get the desktop app to launch. What do I do?

My email on Thunderbird no longer loads on my laptop. It's fine on my desktop. It just stays a blank screen. "No message found" it says. I have to shut it down and when I do it says "Thunderbird is not responding." Can you give me a step-by-step on how to fix this?

I have/had two different problems with the same results. In the first case I get the login window. I enter the password hit return and that window goes away and some times you can scroll to different opened emails before it says "Not Responding". The only action that works is to exit the app. Usually after a few days or weeks it will start working and does so for a few days or weeks. Lately the login window does not appear when the app opens and it displays the "Not Responding" message. It shows that it is "Loading Message". I have tried all of the options from the troubleshooting window and reinstalled Thunderbird with no change in response> Where do I go from here?

How do I deselect multiple folders selected it didn't happen until today and now I can't use thunderbird. There is no way to deselect multiple folder and I did not select that option need to move through different emails account and my local folder where I have emails sorted and I need this at I have emails pertained to forms I need to complete in order to submit request for pension. It work perfectly well yesterday prior to recent update. I need access to my emails

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.

Thunderbird is installed on an iMac Retina 5K, 27" 2019 computer running macOS 15.7.6, but just this week, when it starts, it only opens a window with tabs and does not finish opening the app. The window shows the tabs, but they just have a bouncing dot from right to left, and anywhere I move the mouse on the window's control bar, I get a swirling color wheel. I restarted the Mac (no change), deleted the app and downloaded a new one, and nothing changed. Force Quit says it's 'not responding'. What do I do next?

T'bird 153.5.0 esr on Windows 11 25H2.

Main Inbox folder (using POP3) is about 13 GB

Thunderbird crashes and/or becomes unresponsive on opening. This happens in both normal mode and safe mode.

Typically, there first is this error message: "The account is being processed. Please wait until processing is complete to get messages." I click OK on that message, and after a while, Tbird becomes "unresponsive."

I've tried deleting Inbox.msf, but that didn't help.

Sometimes, I get this error: "Unable to write to the mailbox. Please ensure the file system allows you write privileges and you have enough disk space to copy the mailbox." There have been no changes in Windows accounts, so it seems highly unlikely that there is a permission issue.

The hard drive on this system has about 233 GB free.

Where do I go from here?

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