Exchange iCal can't save events

Question

I was wondering if anyone has had a similar issue to this, and could suggest any resolution, as I've been banging my head against the wall for some time over it!!
I have set up a Microsoft Exchange Server Account with email, calendar and contacts all synced between Mail, iCal and Address book, however I am getting an error message that appears on screen in iCal every ten minutes or so saying that:
"iCal can't save the event "xxxxx" to the Exchange server. The account "xxxx" 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. To save your changes on your computer until the problem is resolved, click Go Offline."
It occurs even when I haven't been modifying the events and will continue to pop up throughout the day.
When I check the log file in Console, the errors look like this.
iCal[224]
error = Error Domain=CalExchangeErrorDomain Code=-4 UserInfo=0x115ce5400 "iCal can’t save the event “12.30pm: appt at clinic” to the Exchange server."
16/05/2011 14:23:46
iCal[224]
error = Error Domain=CalExchangeErrorDomain Code=-4 UserInfo=0x115a329c0 "iCal can’t save the event “12.30pm: appt at clinic” to the Exchange server."
16/05/2011 14:33:00
iCal[224]
error = Error Domain=CalExchangeErrorDomain Code=-4 UserInfo=0x115cd9fd0 "iCal can’t save the event “2.30pm: Meeting wkly catch up (18/6/10)” to the Exchange server."
16/05/2011 14:34:59
Does this seem familliar to anyone? Any help would be much apprieciated.
PS I have seen this feed: https://discussions.apple.com/message/10108361#10108361 and have tried it, but with no luck!
Cheers.

Answer 1

I am having the exact same problem. OS X 10.8.1 and Exchange 2010 with all service packs installed. Exchange syncs perfectly with all iOS devices as well as OS X 10.7.x. Upon upgrading to 10.8 (and now 10.8.1), I continually get a message like "Calendar can’t save the event “xxxxxxx” to the Exchange server." After saying "revent to server", I receive the message stating "Invitees not recognized..."
Apple, do you expect to address these issues?
This is the console output:
9/8/12 1:01:54.109 PM CalendarAgent[34024]: [com.apple.calendar.store.log.exchange.queue] [error = Error Domain=CalExchangeErrorDomain Code=-4 "Calendar can’t save the event “Breakfast with Michael Zimbalist” to the Exchange server." UserInfo=0x7fcb233e9870 {NSLocalizedFailureReason=The account "Venrock" 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., CalFailedOperationKey=<CalExchangeUpdateCalendarItemOperation: 0x7fcb23298340>, NSLocalizedDescription=Calendar can’t save the event “Breakfast with Michael Zimbalist” to the Exchange server.}]
and
9/8/12 1:01:53.892 PM CalendarAgent[34024]: [com.apple.calendar.store.log.exchange.queue] [error = Error Domain=CalExchangeErrorDomain Code=-19 "“Breakfast with Michael Zimbalist” had invitees not recognized by the server." UserInfo=0x7fcb21ca7290 {NSLocalizedFailureReason=You entered an invitee that wasn’t recognized by the server., CalFailedOperationKey=<CalExchangeUpdateCalendarItemOperation: 0x7fcb25525940>, NSLocalizedDescription=“Breakfast with Michael Zimbalist” had invitees not recognized by the server.}]
Thanks,
David