Mac Calendar "Server responded with an error" message

It appears my calendars are now working correctly, as of about 9:00am CST all Google Calendars are syncing again and server error has disappeared. Problem started a couple of days ago and all fix suggestions in this discussion were tried, but failed. Looks like somebody on the server side got on this and resolved it.

2019 MacBook Pro 16" , Big Sur 11.2.1

Wait, did it stop happening for everyone? I'm still getting the error, last time at about 4 pm PST. Plus I got a new error on top of it that I hadn't seen before (403? I unfortunately clicked it off before copying the text)!

well.. it was fixed earlier in the day for me but now its busted again... I did nothing to fix it earlier.. so server side issue.. I'm in the DC area behind Verizon.. anyone else in same area or provider? again wondering if it is rolling over with either service load balancing or capacity issues during certain times of the day..

I have 2 Google accounts, one is a Google Apps and one is a personal one. The Google Apps is more important. I was able to fix it by going to Preferences, Accounts tab, and unchecking the Enable this account. Then wait for the calendar to disappear, then recheck the box. You might get the error, then do Try Again, and repeat this process 2 or 3 times. The problem went away!

This only worked on the Google Apps account; my personal Gmail account calendar still will not work.

Update on reproducing this problem - I can make accounts work/not work at will. It turns out the *last* account you enable will work, and all other Google calendars will stop working. So go to Preferences, Accounts tab and uncheck the Enable this account tab on each Google calendar. Then go back to each "less important" calendar and check them. They will start working and sync again. After they sync, go to the next most important one and check that one. It will sync. Finally do your work one and check that one. It will sync - at this point all the other ones will have errors. You'll have to live with that unfortunately until Apple fixes this problem. But at least it is possible to pick one calendar and get it to work.

I'm having same issues as everyone else. I rely heavily on ical syncing with exchange and google calendars for work. Google calendars are still having problems with the error message continuing to come up whenever I put in a new diary entry or try to edit one.

Exactly the same situation here. I followed all the instructions above, including @daviddrahos method - now there's no sync error but all the calendars under my gmail account are missing. This is utter insanity.

I have the same issue. Just started today. Tried deleting the account and re-adding it, tried deleting the calendar agent and the library preferences and calendar data, reset the NVRAM, same issue. Calendar is just fine on Outlook. So clearly an Apple Calendar issue introduced in the last few days. Any other suggestions? Do we know if Apple is aware and working on it? I hate getting on the phone with another apple associate that doesn't know anything and follows a script.

Adding to the tally here. Starting having sporadic issues three days ago, then got worse. 11.2.1 upgrade didn't help. Did the @daviddrahos method and now nothing will show on the calendar at all, none of the above tricks to get even one account (I have one personal google and two business google accounts) to show in calendar. Completely blank with three error icons.

2018 MBP

Giving an update for me it was fixed in the AM and now is not working again. This seems to be consistent with what at least one other person in this thread has said. Some have said sporadic and some have said specifically problems depending on time of day.

I am also still having this issue as of Feb 23, 2021 8:32pm PST. I can no longer trust my computer calendar and must use my phone to be sure I'm not missing my client meetings. This is an URGENT issue. Anyone know the status?

UPDATE

I had to take the nuclear option. I followed the instructions from here for the steps described above (https://www.wikihow.com/Clear-the-iCal-Cache)

They are from 2018 when apparently this problem happened too. It tool less than 3 minutes.

Now my Calendar shows a "Google" calendar but it's not yet populated. I am guessing it will take all night to go over all Contacts and Events in the one account (School) that I added.

One think that I just noticed is that there is now a new (to me) calendar called "Siri Suggestions" that I don't remember being there before I cleared the cache, force quit the app, then restarted the computer. Just mentioning in case someone notices the same thing.

I have this problem too. I worked on it for hours one time a few weeks ago and ended up moving everything scheduled within the past 2 weeks into a shared google calendar belonging to a different account, then moving them back one by one. It was a problem with a single calendar event :(

Exact same problem. Error line on the Console is pasted below. For me, this error shows up till around 12 PM India time everyday (only in the mornings). After approximately noon, it goes away and calendar syncs perfectly without issues for the rest of the day. Error comes back again next day in the mornings. Every day

default 10:15:34.254926+0530 CalendarAgent [com.apple.calendar.store.log.caldav.queue] [Account refresh failed with error: Error Domain=CoreDAVHTTPStatusErrorDomain Code=403

No idea how to solve this yet.

Not only does the suggested fix available elsewhere (to delete the cache files and rebuild the calendar) stop working after a few hours, but when the calendar was rebuilt, all my meetings in other time zones were reset to my time zone. So don't rebuild your calendar if you don't want to lose all the time zone information in all your meetings (VERY annoying, I have to go into each meeting and fix it now!)

Also, this is only on my MacBook. My iPhone is synching fine.