What to do when iMac Calendar shows server error?

2015 MacBook, Monterey 12.7.6

System Preferences

Internet Accounts

Un-tick Google(for me it was Contacts and Calendar)

Power cycle

Calendar works, no server error

Tick Google

Power cycle (just to check)

Calendar still works, no server error

Added a Google calendar event for today

Turned Calendar off and on - Google calendar event appears

SUCCESS

I have had exactly the same problem and in my case it is associated with my Google Account. If I go to System Preferences/ Internet accounts, select my Google Account and then switch off Calendar the problem goes away. Mind, so do all my events, so it is not a useful solution. At this point I tried to add my Google Account via my Calendar app/ Add Account but after I authenticated with Google it pointed out that I had already got that account so I had to quit that plan. However when I re-enabled Calendar in System Preferences I got my calendar events back but the error had gone! I cannot now say if just switching the Calendar access off and the on did the trick or whether my blundering about trying to add Google again did something but at least, for me now the problem has gone.

This worked for me just by turning off calendar and then turning it back on in my google accounts under System Preferences/ Internet accounts - I did not try to re-create the calendar account - thank you so much - this has been such a major toleration!!

THANK YOU THANK YOU THANK YOU!! This has been bugging me for months. Simple off and on google Calendar in system settings (internet accounts) did the trick! no rebook required inbetween the on and off. Gosh that so great that it works! HNY

I was able to resolve by removing and then reinstalling the Gmail account from the Mac Internet Accounts.

(Correction: I mean, deleting the account completely and setting it up again.)

Yes - caused by a Google Mail account.

Thanks for that. I thought that turning access off and back on was the key but as I had muddied the water by trying to re-crate the account so I figured it was better to tell the whole story. Presumably there is some stale data cached somewhere that turning on/off flushes out.

This is insane. I can't use Calendar.app anymore, it's blocked by a permanently recurring server error. All I can ever do is force-quit it. Turning the account off an on didn't help. Deleting the account completely didn't help.

I have the same problem. The solution presented here does not work for me. When the problem occurs,I have to restart my computer to make the error go away until it comes back again. I can't even use the activity monitor to force quit. Very annoying.

I am having the same issue. Did you find a solution?

I can't find an option to force quit Apple calendar, but have the exact same problem

Same issue suddenly on all my macs. Solutions anyone?

ok this happened to me yesterday (Nov 18) and I am searching for solutions. My Mac is 2015 on Big Sur and does not get any updates anymore.