CalendarAgent continuous error generation in MacOS 10.12.4

Solution 1:

The possible problem is that database schema or some of database entries are incompatible with latest Calendar app. Or may be these entries are corrupted.

There are 2 possible solutions:

• fix db which is tricky.

• drop db - it's just cached data of your cloud accounts.

to do the 2nd option:

• stop Calendar App (ctrl+q), then
• open ~/Library/Calendars and
• remove Calendar Cache files (you may just trash them)
• start Calendar App again.

You will need probably reactivate your calendar accounts.

To do so, open calendar app settings and choose desired accounts in accounts section