Calendar will not launch under Mojave. It starts to load then crashes.

Like Ronald Stephens from Nov 2018, https://discussions.apple.com/thread/8611349, my calendar loads to a blank calendar, then it says it is Updating calendars, then crashes at the 3/4 point on the third or fourth blue updating screen. I then get this message of why it crashed:

Time Awake Since Boot: 420 seconds

System Integrity Protection: enabled

Crashed Thread: 0 Dispatch queue: com.apple.main-thread

Exception Type: EXC_CRASH (SIGABRT)

Exception Codes: 0x0000000000000000, 0x0000000000000000

Exception Note: EXC_CORPSE_NOTIFY

Application Specific Information:

dyld3 mode

*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '*** +[CalEntityDescription insertNewObjectForEntityForName:inManagedObjectContext:obtainPermanentID:]: could not obtain permanent id for BirthdayCalendar with error Error Domain=NSCocoaErrorDomain Code=134020 "The model configuration used to open the store is incompatible with the one that was used to create the store." UserInfo={NSUnderlyingException=Can't resolve how to assign objects to stores; Coordinator does not have any stores}'

terminating with uncaught exception of type NSException

abort() called

Unfortunately, Mr. Stephens never reported back on whether or not he or Apple solved his problem.

To re-cap all the suggestions on that original post and on others;

Yes, Calendar launches successfully in a new admin account.

No, Calendar does not launch successfully in Safe Mode.

No, Calendar does not launch successfully after a re-install of the OS.

Observations-

1-When launching in a new Admin acct, Calendar does not try to update the calendars.

2-Mr. Stephens and my Crash Reports both state the same issue, "could not obtain permanent id for BirthdayCalendar..."

If creating a new Admin acct "solves" the problem, can I not simply keep the new acct and delete the old one?