I would guess the two things are related. What are the crash report ids? See https://support.mozilla.org/en-US/kb/mozilla-crash-reporter-tb#w_viewing-crash-reports

Curiously, the last crash report listed is early December - well before this started happening.

Apparently, whatever is going on it's not a crash, per se.

No further responses to this I see. Am I the only one experiencing the issue? None of the last few updates have resolved it, but I have done a bit of snooping myself.

Essentially in my case when I run Thunderbird there are two instances of the Thunderbird .exe running and active under Apps (viewed using Task Manager). When I close Thunderbird those exact same two instance move down to Background Processes - and remain there.

If I do nothing, trying to restart Thunderbird will just spin the Windows icon (that indicates a background task) round and round but nothing will even happen. I've waited up to a half hour, but it never restarts - unless I first use TM to kill the two background processes. After that it will start as normal.

Similarly, with the latest update I clicked the Restart to Update Thunderbird button (which apparently uses a different shutdown process), went to take a shower, got dressed and came back and it was still hung and had not fully shut down. There are NO crashes in the crash log from this - it just hangs indefinitely, not registering as a crash.

I twiddled some settings, including "Use background process to update" but none of these made any difference. If I could export all settings and config I would be willing to uninstall and reinstall (I have numerous accounts in use).

What is there to respond to. No crash reports means no data to look at.

Are you the only one, I have no idea. Have you tried the standard diagnostics to see if you can narrow the issue.

1. Does Thunderbird work as expected in Thunderbird troubleshooting mode?
2. Does Thunderbird work as expected with your OS started in safe mode with Networking. Instructions for each operating system: Windows 10/11, Windows 8, Windows 7, OSX

As noted in the OP, I can't get it into Troubleshooting mode. This initiates the restart process that hangs with 100% reliability, and after I force a closure and launch again, it's back in normal mode.

Haven't tried Win11 safe mode yet, and due to the nature of the hang am dubious but will give it a go a little later today and report back.

Curiously, the last crash report listed is early December - well before this started happening. Apparently, whatever is going on it's not a crash, per se.

Still, you should post your crash IDs here using the instructions link provided by Matt.

As noted in the OP, I can't get it into Troubleshooting mode. This initiates the restart process that hangs with 100% reliability, and after I force a closure and launch again, it's back in normal mode.

Your description suggests you have not done ... Hold down the Shift key while starting Thunderbird.

Just to clarify: you mean select Troubleshoot mode, and hold down Shift while it restarts?

I did try that, and it makes no difference; Thunderbird just grays out and stops responding. if I click the X Windows will say it's no longer responding. If I misunderstood, please correct me.

I will try Win11 safe mode shortly.

Last crash ID was: a1e86a84-65ae-485a-894f-e6a04d734e08. This is dated the 12th of last December though, well before this issue began.

The one before that was last September, and it was: 249d716b-1a54-4ffd-9b41-a299a16dc8e4

This kind of issue is bound to occur if you're a Beta Tester. Right now, version 115.8.1 is working well, except for a small filtering problem I found.

Just to clarify: you mean select Troubleshoot mode, and hold down Shift while it restarts?

No. Starting in Troubleshoot mode means, with Thunderbird NOT started, hold shift key and click on Thunderbird to start it. You will then see ...

This kind of issue is bound to occur if you're a Beta Tester. Right now, version 115.8.1 is working well, except for a small filtering problem I found.

Respectfully disagree that all beta users can expect problems, although yes the likelihood is greater on beta. I for example rarely have issues and I use beta all the time.

Also for the problem described here there are no reported bugs for 124.0b1 and newer which match this issue. And 124 beta has been out for a long time, almost a month.

I recognize that in accepting Beta there are definitely more possible issues, and to be fair Beta has been pretty darn solid for me up until this point - and even this is not a terrible one. It works fine, just doesn't seem to want to shut down properly. And bear in mind I am not complaining, just trying to see if anyone has had similar issues in the hopes that if it's a common one this could be helpful feedback.

So far it seems to be fairly unique, which surprises me because it definitely started suddenly with a version upgrade, and never occurred previously.

Wayne Mery said

No. Starting in Troubleshoot mode means, with Thunderbird NOT started, hold shift key and click on Thunderbird to start it. You will then see ...

Ah, OK, now I understand.

Doing so correctly starts it in Troubleshooting mode, but after I shut it down the .exe still linger in the Background Processes, and it won't restart unless I kill those first.

This is one of those times that I did not read with sufficient care. It's natural that startup would fail if the previous shutdown did not complete in a timely manner. So the only problem here is that your shutdown hangs.

Do you have a primary password set? It's the password that protects your account passwords.

Yes, primary and all passwords set. Starting Thunderbird, it logs in correctly and retrieves new emails just fine, and continues to do so during the duration of the that session.

If it is the password-related bug, the is not yet a solution for that. So you when you shut down Thunderbird just kill the task and you should not have a problem starting up.

Thanks. That's what I've been doing so far.

Is there a # for the password-related bug so that I can read the description and see if it's the same thing?

There are multiple https://mzl.la/49eFti1. It's possible that yours is not an exact match. It would be easier to get a match if you were actually crashing and had crash IDs.

I see why you asked the Q. 154247 sounds just like the behavior I see, except (as I noted) the PW is entered.

Not at all familiar enough with the workings of Thunderbird to even speculate what may be at play, but hopefully it'll be figured out soon. This is still the best mail app out there.

A few additional data points on this: I backed up my settings and completely uninstalled/reinstalled Thunderbird, even putting the reinstall on a different drive (my main PC has 5 drives) and the issue persists identically.

I thought maybe the "empty trash on exit" could be an issue, since this only affects closing Thunderbird, so cleared that on all my mail accounts, and again, no change.

So not a bad or corrupted install, and not caused by "empty trash on exit" either.

So far none of the updates have addressed it either, so it remains "at large."

I have just started having this problem since updating to 115.10.0. Windows 11 Pro 23H1