BE 2012 - Restore is empty

Hi,

i just upgraded a server of a customer to 2k8 R2 and BE2012.

Now he needs a restore of some old data. We did create a full backup on 2 tapes before the upgrade, so this should be no problem. ( In BE 12.5)

I inventorizied and rebuild the catalog (just right click on both on the tapes and "inventory and catalog").

I can see all data I need in the restore dialog, I can successfully start the recover and the recovery ends successfully.

But no data is restored, not even a single file or folder.

any idea?