Thanks for the replies.

..it shows "safemode" on the screen as starting BIAB, I wanna ask what is the difference between "safemode" and other modes. Any function was stopped?

Yes, if you see 'safemode' on the splash screen, that confirms it's working. This is mainly a troubleshooting mode. It runs the program as if it's at factory settings, so it will indeed ignore your personal settings. Mainly it is a convenient way to try the program with the default configuration without having to trash your preferences. So it's not a "long term" solution (safemode.txt in the Preferences folder).

The other way to get to factory settings is to just delete the contents of your Preferences folder. Prior to doing that, you should duplicate the folder (click on it and press Command+d, and name it something like Preferences_backup_11-24-2020) then you have the option of restoring your preferences later if need be and you don't need to worry about accidentally deleting an important file.

The reason I asked the specific questions in my last post, is that (a) it seems that some people need to clear the Preferences each time they boot the program, and (b) this seems to be a plugin related problem.

Opening the "Plugins Dialog" crashes BIAB.

Are others able to open the Plugins dialog? And if so, can you check the list of plugins and try excluding (non-Apple) plugins and see if that fixes the problem?
PG Music Inc.