So I came across this “challenge” when trying to move a user from Exchange 2010 SP3 to Exchange Online.
All the others users in the batch worked fine, but one user would get to around 50% and then fail!
The batch log contained:
09/11/2017 17:42:55 [HE1PR04MB2985] User xx.xx' failed migration: Error: ASSERT: Reservation to update is not found
The user log wasn’t much better with:
09/11/2017 17:38:47 [HE1PR04MB3241] Fatal error ExAssertException has occurred.
MigrationMRSPermanentException: Error: ASSERT: Reservation to update is not found
So I tried something that I have done before. Using PowerShell and connecting to EXO, I ran:
Set-MoveRequest -Identity xx.xx -SkipMoving: FolderRestrictions, KnownCorruptions, FolderViews
I then restarted the batch
Start-MigrationBatch "yy_yy" -Verbose
And BOOM! it worked. Not sure what the hell was going on but hey, the user moved!
Hope this helps someone ;-)