The error pops-up during step 2 granular restore (VSS-Aware for Exchange sets), when using the "emails" option.


The mailbox selected to be searched was moved from the database originally backed up into to another mailbox database.


Ensure the mailbox is located in the same database that was restored (for example if mdb-01 was backed up and at that time the mailbox user1 containing the items intended to be restored was located in this database mdb-01, ensure that when attempting the step 2 granular restore with the "emails" option, the mailbox user1 is still located in the production database mdb-01).