Recently ran into an issue with Calendar causing a huge CPU spike. Checking the system.log I noticed the following repeatedly in my log:
CalendarAgent Unexpected EOF, returning last token as fallback
CalendarAgent is essentially Calendar’s backend (that’s how it’s also able to power the notification center). The best resolution I’ve found is to completely clear out the calendar and recreate it. Process I used was as follows:
- Remove the Calendar from “Mail, Contacts & Calendars” pref panel (just uncheck from the account). Then go into Calendar and make sure the account is removed. If it’s not, remove it.
- Go back into the “Mail, Contacts & Calendars” pref panel, put the calendar back. Give it some time to download.
That seems to have worked for me.