Bugzilla

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:75.0) Gecko/20100101 Firefox/75.0

Steps to reproduce:

Opened Thunderbird this morning as usual - program showed my mail folders in sidebar but never loaded main content window.


Actual results:

* Main window remained blank, cursor spinning, program frozen. Unable to perform any actions except force quit. 
* Deleting and reinstalling program did not correct the issue. 
* Creating new, empty profile worked, BUT mail settings are erratic - Thunderbird refuses to retain selected signature file, will not allow addition/edit of an IMAP mail directory in Server -> Advanced. It is as if the program cannot retain any changes I have made.


Expected results:

Program should open mail as expected. Settings should be changed when I change them. If profile changes are needed, program should migrate profile settings to new format. Have never had to manually rebuild my entire profile in a decade-plus of using Thunderbird.