Hi,
when doing mailbox moves between Exchange 2010 and Exchange 2013 (CU3 and SP1) and also between two Exchange 2013 SP1 servers we experience the following issue:
sometimes a new empty default calendar folder is being created after the mailboxmove completes. Out of 230 moved mailboxes 6 mailboxes experienced this issue. For some reason the existing calendar folder is changed to a user created folder and a new calendar folder gets being created. This causes some panic by the affected users, since they suddenly notice that their calendar is completely empty. The free/busy information other people see is also empty because they also see the empty calendar.
To correct the issue I have to manually move the items from the original calendar folder to the newly created calendar folder.
Any idea what might cause this? I don't have reproduction steps, it just happens at random during the mailbox move. The moverequest completes succesfully, no errors are reported and the movereport also doesn't contain any clues.
Frank.