Symptom:

When you create a new database in exchange 2013 CU9 and move the arbitration mailboxes from the default database to the new created database on the same server, you may get the following error when click on migration in EAC:

==========================
error:
Failed to load the migration item with id xxxxxxxxxxxx. Please try again later. Run Get-MigrationBatch in EMS, you can also see the same error like below:

[PS] C:\Windows\system32>Get-MigrationBatch | fl
Failed to load the migration item with id xxxxxxxx..xxxxxx. Please try again later.

+ CategoryInfo          : NotSpecified: (:) [Get-MigrationBatch], CouldNotLoadMig...nsientException + FullyQualifiedErrorId : [Server=EX2013SVR,RequestId=a8c53932-a0b1-481a-b3ed-1c102a41ba69,TimeStamp=08/07/2015 13:25:54] [FailureCategory=Cmdlet-CouldNotLoadMigrationPersistedItemTransientException] 6054BE1D,Microsoft.Exchange.Management.Migration.GetMigrationBatch+ PSComputerName        : EX2013SVR
===========================


Cause:

It is due to the arbitration mailbox has been corrupted, you need to delete and rebuild the arbitration mailbox which is corrupted.


Solution:

Please try the following method to resolve the issue:

1. Find out the corrupted mailbox , you can run the following command to check which user is being migrated:

Get-MigrationUser |fl Identity

2. In ADUC(Active Directory Users and Computers), delete the user which got from setp1

3. Run the following command to prepare AD again, it will rebuild the user:

setup /preparead/IAcceptExchangeServerLicenseTerms

4. Enable mailbox for the user again:

Enable-Mailbox -Arbitration -Identity "Migration.xxxxx"

Set-Mailbox "Migration.xxxxx" -Arbitration Management:$true

5. Try migrating again.