Thunderbird crashes on startup with ErrorLoadingBuiltinSheet. bug 1194856
Thunderbird 45.2.0 on Windows 10. We upgraded to windows 10 a few weeks ago, but it was still working fine until today.
Every time I run it, it immediately crashes. Even when I run it with thunderbird.exe -safe-mode it still immediately crashes. It just immediately says "We're Sorry" and has the crash reporter. Here is one of the crash reports in normal mode https://crash-stats.mozilla.com/report/index/4148d2cd-b017-44e6-be1d-cf9ff2160721 here is one in safe mode https://crash-stats.mozilla.com/report/index/84e997dd-7a45-4a82-a9c8-201902160721
It looks like it is this bug https://bugzilla.mozilla.org/show_bug.cgi?id=1194856
I uninstalled Thunderbird, and reinstalled it, and the problem is still there.
I backed up my stuff with mozbackup, then uninstalled Thunderbird, then deleted AppData\Roaming\Thunderbird and AppData\Local\Thunderbird . Then reinstalled Thunderbird and it worked (without any emails). Then I exited Thunderbird and restored the emails with mozbackup, and it went back to not working again.
Wot Wayne Mery
Wšě wotmołwy (1)
Good research.
No fix in sight in the bug report, and no workaround listed. https://support.mozilla.org/en-US/questions/1127088 solved by reinstalling and restoring a backup, but apparently that didn't help you.
I don't have a workaround to offer. But I'm not certain the bug report is a good match for Thunderbird users. I suggest you try in the web interface for your mail system deleting/moving messages with date+time in the vicinity of when you started crashing. Is that possible?