We have a user on Exchange 2013 who recently got thousands of duplicate calendar entries. By the looks of it happened overnight/over the weekend about 2 weeks ago and now there is no way to get rid of them.
The Calendar entries are definitely in Exchange and not just stored locally. OWA showing thousands of reminders and thousands of Calendar entries. Outlook clients as well as OWA are unusable - as soon as you click on Calendar it crashes freezes and then crashes Outlook client as well as every single browser I tried it on.
I tried everything I could find online, there isn't much, as most of the solutions only deal when the problem is limited to the Outlook client.
Also ran a CalCheck on the Mailbox in question and that's what I get
Found 4267 items in the Calendar. Processing...
ERROR: PidLidGlobalObjectId and PidLidCleanGlobalObjectId values match on two items.
Properties to help investigate this reported item:
This Item Subject: *redacted*
Start Time: 01/06/2013 08:00:00PM
End Time: 01/06/2013 08:30:00PM
Other Item Subject: *redacted*
Start Time: 01/06/2013 08:00:00PM
End Time: 01/06/2013 08:30:00PM
Many mobile devices that sync through Exchange Active Sync will not sync items that have
duplicated GOID properties, so one of the above items may not show on a device if it is in use
with this mailbox.
Please see the following article for additional information: http://support.microsoft.com/kb/2714118
ERROR: Detected a duplicate item in the Calendar. Please check this item.
Properties to help investigate this reported item:
Subject: *redacted*
Location:
Start Time: 01/06/2013 08:00:00PM
End Time: 01/06/2013 08:30:00PM
Last Modifier: *redacted*
Last Modified Time: 04/14/2014 10:52:34PM
Recurring Appt: true
Sender Name: *redacted*
Sender Address: *redacted*
Organizer Name: *redacted*
Organizer Address: *redacted*
Recurrence Start: 01/07/2013 09:00:00AM
Recurrence End: 09/01/4500 09:29:00AM
Recurrence End Type: No End Date
Occurrence Count: No End Date
Number of Exceptions: 0x0001
And 6 more Megs of the same repeated log.
Looks like there are under 10 entries that got multiplied hundreds of times each.
Any ideas? Otherwise my next step is to create a new mailbox for the user and do Export/Import on it.