Calendar Imports were working fine for a long time then suddenly stopped. I would imagine this has something to do with an update google possibly made?
Occurs on D9/D10
The error happens when trying to sync new events, the is error below.
TypeError: Drupal\google_calendar\GoogleCalendarImportEvents::parseCRUDDate(): Argument #1 ($event) must be of type string, null given, called in /app/modules/contrib/google_calendar/src/GoogleCalendarImportEvents.php on line 732 in Drupal\google_calendar\GoogleCalendarImportEvents->parseCRUDDate() (line 1008 of modules/contrib/google_calendar/src/GoogleCalendarImportEvents.php).
Active
3.0
Code
I ran into this issue trying to access a company calendar that had restricted permission to see only "free/busy", not "see all event details."
Not sure if that's helpful, but wanted to note it since I found this issue troubleshooting the same thing.
Have you updated the vendor/google files recently?
My own calendar is still working fine, so it seems this is not general (unless there is some sort of roll-out going on)?