I'm having a problem with Calendar and Exchange syncing (my company uses Exchange 2010), with the following error:
"Calendar can’t save the event “Item title” to the Exchange server.
The account "Exchange" currently can’t be modified. To discard your changes and continue using the version of your calendars that’s on the server, click Revert to Server."
The options on the dialog box are:
Revert to Server
Syncing in general is working, i.e., items added in either system show up as they should. And, I'm not actually changing anything on the items on my MBA. The error pops up apparently randomly--so far, at least, I haven't been able to identify a pattern. I've checked credentials, which seem to be correct, and I've verified that time zone settings are turned on as I think they're supposed to be.
I also experianced this problem after an upgrade to Mountain Lion.
I think it has to do with the fact that in Lion the account settings were managed from iCal, and now they are managed by the OS?
Anyway I finally solved it by:
- Open Calendar (formerly iCal).
- Go to the Calendar menu and select Preferences.
- Select the Accounts tab.
- Remove the Exchange server account which is giving you the error messages. This calendar will be removed from the Calendar app.
- Go to System Preferences and click on the "Mail, Contacts & Calendars" pane, find your Exchange server account, and check the "Calendars & Reminders" option to re-enable your calendar.
- Your Calendar should now sync properly.
I had to do this for all of the accounts I had set up in Calander, and haven't had any problems since.