User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:92.0) Gecko/20100101 Firefox/92.0

Steps to reproduce:

OS: Win 10 21H1, TB: 91.0.3 (64-bit)
TB randomly freezes after receiving a new email notification, most notifications work fine. When this occurs the notification is completely blank and can not be closed. Hourglass "busy" cursor shows in TB and can take no actions. Must kill process in task manager and restart TB. Problem started after upgrade from TB 78 to 91.0.

What happens if you start Thunderbird in https://support.mozilla.org/en-US/kb/troubleshoot-mode-thunderbird ?

(In reply to Wayne Mery (:wsmwk) from comment #1)

What happens if you start Thunderbird in https://support.mozilla.org/en-US/kb/troubleshoot-mode-thunderbird ?

Thank you, currently running in Troubleshoot Mode, though I have no installed extensions or any custom settings. I'll let you know what happens.

Do you have a language pack installed?

Start Windows' safe mode with networking enabled

• win10 https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode
  Still In Windows safe mode, start thunderbird in safe mode
• https://support.mozilla.org/kb/safe-mode-thunderbird

Does problem go away?

Sorry I haven't responded back to this. I'm now currently using TB 91.1.2 (64 bit) and I'm still experiencing the issue. A little more info though: I have two monitors, a 24 inch HD monitor and a 43 inch UHD smart TV/monitor, both connected via HDMI on a video card. They are configured in Windows in a top/bottom configuration with the 24 inch monitor on top as the main window.

It seems that the issue only occurs when I open TB in the bottom window. I'll get notifications on the bottom screen at the start, but later the notifications appear on the top screen. Sometimes the notification on the top screen is only half visible as if the notification bubble isn't tall enough to contain the note and even cuts the TB logo in half. Other times when the notification bubble is at this "half" height it may take several seconds for the info to populate it during which time TB will not respond. Other times the notification bubble never populates and TB then must be closed via Task Manager or Process Explorer.

I have noticed that TB normally runs with 2 instances of thunderbird.exe in the process tree, but when the error occurs there is only one. Running TB in the top monitor does not seem to create the issue. Running TB in Troubleshoot mode does not make any difference. I have yet to try running it in Windows safe mode simply because the issue is random and may appear at the start of TB or several hours later. I have added a PNG attachment of the empty bubble.

Just noticed this new symptom. The Notification is split between the two monitors, TB locks up.

Dual monitor users (or not) ... can anyone else reproduce this?

(In reply to broknsymetry from comment #0)

OS: Win 10 21H1, TB: 91.0.3 (64-bit)

Any better with 91.2.0?

(In reply to Arthur K. [He/Him] from comment #8)

(In reply to broknsymetry from comment #0)

OS: Win 10 21H1, TB: 91.0.3 (64-bit)

Any better with 91.2.0?

I've had it running for several hours today and problem just re-occurred., so no, 91.2.0 does not help. :(

Just set "Use the system notification" in the "Incoming Mail" preferences; will see how that goes.

(In reply to Wayne Mery (:wsmwk) from comment #7)

Dual monitor users (or not) ... can anyone else reproduce this?

I just changed settings to use system notifications. Let's see if I will be able to reproduce this. I'm mostly connect to a second display (TV) for entertainment, so it's close to the reporter's setup. So far, after several messages sent and received between my accounts, I haven't experienced any lagging or lockups. Windows also draws the notifactions as fast as for any other application. Let's see how things go in the next few days. With busy accounts in Thunderbird and about 15 hours of system uptime every day, this shouldn't take long to reproduce if it really is Thunderbird's fault. Also, I have four Thunderbird processes in Task Manager.

Though technically not a fix, using the system notifications instead of the TB notifications appears to have eliminated the blank notifications and hangs. The problem with the TB notifications should still be investigated, but I'm happy with the results as of now.

(In reply to Stans from comment #10)

(In reply to Wayne Mery (:wsmwk) from comment #7)

Dual monitor users (or not) ... can anyone else reproduce this?

I just changed settings to use system notifications. Let's see if I will be able to reproduce this. I'm mostly connect to a second display (TV) for entertainment, so it's close to the reporter's setup. So far, after several messages sent and received between my accounts, I haven't experienced any lagging or lockups. Windows also draws the notifactions as fast as for any other application. Let's see how things go in the next few days. With busy accounts in Thunderbird and about 15 hours of system uptime every day, this shouldn't take long to reproduce if it really is Thunderbird's fault. Also, I have four Thunderbird processes in Task Manager.

It isn't the system notifications I was having difficulty with, it was the native TB notifications. If you were not having issues before switching to the system notifications then I suspect the issue is with my PC.

I must have misunderstood your previous comment "Just set "Use the system notification" in the "Incoming Mail" preferences; will see how that goes.", it read like an instruction to do as it says to reproduce your problem. I have had no such problems with native TB notifications.

(In reply to Stans from comment #13)

I must have misunderstood your previous comment "Just set "Use the system notification" in the "Incoming Mail" preferences; will see how that goes.", it read like an instruction to do as it says to reproduce your problem. I have had no such problems with native TB notifications.

Sorry about that, I meant it as a troubleshooting step.

Hello @broksnymetry

In order to verify if the behavior described in #1740928 is the same, can you check if you have Unified Folder view enabled? And if so, disable it and check if the freezing disappears.

(this is obviously a workaround, users need to be able to use Unified Folders without being forced to open the slow-loading Unified Inbox)

Thanks!

(In reply to Benjamin Bach from comment #15)

Hello @broksnymetry

In order to verify if the behavior described in #1740928 is the same, can you check if you have Unified Folder view enabled? And if so, disable it and check if the freezing disappears.

(this is obviously a workaround, users need to be able to use Unified Folders without being forced to open the slow-loading Unified Inbox)

Thanks!

No, I have "All" set. Using system notifications has "solved" this issue for me.

Thanks.

FWIW https://mzl.la/3cJiXD0

Does this reproduce in version 102?

(In reply to Wayne Mery (:wsmwk) from comment #18)

Does this reproduce in version 102?

I am currently running TB 102.3.0 with "Use the system notifications" still selected and not experiencing any problems. I have not checked if the problem occurs without system notifications.

Resolved per whiteboard and Comment 19