I've been using Thunderbird for I don't know, but about 20 years or so - and I think in total it crashed a handful of times in that duration. Wow.
Recently however, after updating to v68.7.0 (Xubuntu 18.04.4) Thunderbird sometimes refuses to start, and I immediately only see the "Mozilla Crash Reporter" dialog. Trying to select "Restart Thunderbird" just crashes it again
Opening it from the commandline, shows the following messages:
console.log: WebExtensions: Loading packed extension from /home/pb/.thunderbird/jfnwvogr.default/extensions/{58D4392A-842E-11DE-B51A-C7B855D89593}.xpi
console.log: WebExtensions: Loading packed extension from /usr/lib/thunderbird/extensions/{e2fda1a4-762b-4020-b5ad-a41df1933103}.xpi
console.log: WebExtensions: Loading add-on preferences from /home/pb/.thunderbird/jfnwvogr.default/extensions/{58D4392A-842E-11DE-B51A-C7B855D89593}.xpi
console.log: WebExtensions: Firing profile-after-change listeners for {58D4392A-842E-11DE-B51A-C7B855D89593}
console.log: WebExtensions: Loading add-on preferences from /usr/lib/thunderbird/extensions/{e2fda1a4-762b-4020-b5ad-a41df1933103}.xpi
console.log: WebExtensions: Firing profile-after-change listeners for {e2fda1a4-762b-4020-b5ad-a41df1933103}
[calBackendLoader] Using Thunderbird's builtin libical backend
console.warn: Overlays.jsm: Could not resolve 1 references Array [{}]
ExceptionHandler::GenerateDump cloned child ExceptionHandler::WaitForContinueSignal waiting for continue signal...
15511
ExceptionHandler::SendContinueSignalToChild sent continue signal to child
[SOLUTION]
The problem disappears after restarting the computer. Since I'm not a Windows user, this is not a solution.
I haven't found out what causes this yet. I'm not sure, but I think it only happened after resuming from a longer suspend.
To be continued!