I am having Firefox crash on startup much like [https://support.mozilla.org/en-US/questions/1519017 Firefox Desktop crashing on startup], initially in version 140, but I have downgraded to version 139 in my troubleshooting and I'm getting the same symptom. It is frustrating that this does not seem to leave any records in the Windows event log or the Firefox crash reports, and that the fact that there's a known issue of this severity is rather hard to find.