Ventura not syncing exchange/outlook calendar entries

I had this same issue when I upgraded to Ventura. I found there is a process called exchangesyncd that controls the sync with the calendar app (and probably other things like contacts, notes, etc). The point is that I was able to go into Activity Monitor (use CMD + Space and type activity monitor in the search bar), and then type exchangesyncd in the search field within Activity Monitor, do a force quit on it (select the process on the list and then hit the X shaped button on top then force quit). It will take several seconds for the process to restart by itself, and then a few more seconds for the sync to start working on the calendar app. It took maybe 20 seconds in my case to start seeing the calendar sync again.

I remember back in Monterey I had this issue pop up every now and then. A full restart would fix it, but then I found a process called calendaragent and I would do the same thing I described above. Calendaragent is now gone in Ventura, but my guess is that exchangesyncd replaces it, as it behaves the same way. Hope this helps out!

I've had this under Monterey already (and it fixed itself on some update, somehow), but it now cropped up again under Ventura.

For me, a /kill of exchangesyncd ends up being only a partial fix, as symptoms will re-occur (calendar will stop syncing) after a short while. So, after looking into this thoroughly, here's what has worked for me and has fixed this for good. I've been running without the problem for a couple of weeks now.

• If you have the issue the way I had it, then exchangesyncd will manifest 35%+ of CPU load and together with the calendar daemon basically solidly load your efficiency cores (see Activity monitor). That, btw., has side effects on other things like backup (slow) mail (slow), etc., so don't try to work around the issue by restarting it every hour in cron. :) Also, btw., eventually the system scheduler process will realize this issue and quietly kill exchangesyncd... which is when things stop syncing.
• After much digging into what it's actually going on when it churns like that, it seems that the culprit is the sql database that keeps the appointments locally. It is in a faulty/corrupted state post the OS upgrade. Obviously not something you can manually fix, so I went to remove it (so it'd rebuild itself).
• I quit the Calendar app, then deleted my Exchange Account (System Preferences). Then I deleted the database files.
• The three files to delete are: ~/Library/Calendars/Calendar.sqlitedb* - so the three files in there that start with "Calendar.sqlitedb".
• Now, reboot, for reasons. :)
• Then, re-establish your Exchange account, the database files will re-appear, after some syncing (could be an hour) you should be fine and exchangesyncd should be running in th slow single CPU% digits. Enjoy.

• BUT! Side Effect: If you are running iCal calendars in parallel to your Exchange calendar in the native Calendar app (and if they're running secure), then the removal of those database files will also delete required access data from the Calendar app's reach (the app will throw an error for iCal calendars that are switched on). To fix that secondary issue, you'll need to log out of iCloud entirely on that machine (System Preferences), reboot, then log back in. This will re-create the needed access data. Voilà.

TomixM's solution worked for us: Ventura not syncing exchange/outlook cale… - Apple Community

When the macbook starts up the exchangesyncd process will show it's utilizing 40-60% of the CPU continuously. Killed the process and opened the mac calendar, refreshed the calendars and the process showed 2.5% CPU during the sync and quickly returned to 0%. Verified in Outlook365 online that calendar items added in the mac's calendar are showing up in outlook online.

Apple, get it together.

Today I found this page: https://macreports.com/exchange-calendar-sync-not-working-in-macos-monterey/, and the steps presented there solved the problem for me (Ventura 13.2):

1. In Calendar, go to top menu bar "Calendar" and open Accounts
2. Un-install the Exchange-account
3. Restart the mac
4. Install the Exchange-account again

I also tried to remove the Exchange account, then I restarted the macbook and finally I added the Exchange account again among the "internet accounts": it actually seems to work. Calendar syncs with Exchange again!

I am on Ventura.

I deleted and re-added my Exchange account under 'Internet Accounts'

For me, that seemed to fix it.

Well, except for Apple birthdays.

But interestingly, Exchange birthdays may be working. I had given up on that ever working.

@kohster

i actually deleted and re-added my account in 'internet accounts' and it seems to be working fine on ventura 13.0.1.

also have outlook installed, pointing to hotmail. That calendar has always been pretty accurate so I didn't really notice the iCal issues until a few weeks ago.

All, I have now tried all suggestions including the one by TomixM and now seem to working again after a couple of stressful weeks. thank you to all.

In addition to TomixM suggestion, I also restarted, deleted the 365 account from my MacBookPro, added back in the account, left is a bit and after about 30 mins or so it started to sync, phew..

Try enabling exchange mail and sync up with the mail app. After that your calendar app should work and you can disable mail if you like.

I had your exact same problem. I fixed it by removing the exchange account from the mac and then adding it back. Now Calendar and Exchange sync again.

What TomixM mentioned is what also working for me. Restarting the exchangesyncd process make calendar work again. I found that every time I change wifi connection, I need to kill exchangesyncd so that calendar sync again. Don't know what make that process fail in the background.

I had massive problems synching my work Exchange email account, with varying degrees of dysfunction across three or four Macs synching with the same Exchange account, on macOS11 and now on 12. I had to call in external tech support; they suggested disabling the IP-address tracking blocker in Mac settings/network. It immediately started working.

Not sure if there is causality here. That tech support is not an apple specialist. But for now, it appears to have solved the problem.

Try to DELETE your Exchange Internet account and re-add it. I did it once a few months ago and haven't had any problems with my calendar.

After reading the activity monitor tip I tried to use that, but I had no exchangesyncd activity, but under calendar I found one about ical weather. I killed that off and suddenly all my calendars came back almost instantly.

Worth a try? It worked for me.