Exchange Admin Improvements Announced at Microsoft Ignite 2019

Grzegorz Wierzbicki navgupta 

I had this same issue with the Get-EXOMailboxFolderStatistics cmdlet.  What I found was that using the mailbox's Guid for the -Identity parameter would produce this problem.  When I instead used the mailbox's ExternalDirectoryObjectId value for the -Identity parameter, the problem went away.

This tells the issue here has to do with the new Identity parameter.  I hope this information can be helpful in resolving not only Get-EXOMailboxFolderStatistics, but also Get-EXOMobileDeviceStatistics.  I'm sure it's slightly different though seeing as the -Identity parameter on the latter would (I assume) be expecting the mobile device's ID, not a user's, so my solution doesn't quite seem to transfer over in this case.