Hi Bob,
The first thing I would ask the customer to do is to get a crash log so you could post it here.

If you have them navigate to and launch "/Applications/Utilities/Console.app", then in the column on the left click on "User Reports".

There you will see all the BIAB crashes listed by date.
If they select an entry, the crash log shows in the right side of the window, then they can copy/paste it in an email to you.

If you can post the log here or send it to PG support, the PG folks can probably help, they are really good a deciphering the crash logs.

Hopefully this helps !

- Jay

MacPro 5,1/12 core@3.46GHz -- OS X 10.15.7 -- ATI 7970 -- 32 Gig RAM -- Crucial 500GB OS SSD -- Samsung EVO 1TB Audio/Sample SSD -- BIAB 2024 -- Logic Pro X -- Cubase Elements 14 -- Too many plugins