Attempting to browse a client restore session generates the error "Corrupted Backup Index".
This can happen if the NetVault Backup client software release is higher than the NetVault Backup server software release.
This is because later versions of netvault changed the way they write the backup index in the database and older versions are unable to read the index in the new format.
Ensure that the NetVault Backup server software release is the same version or a higher version than that of the clients it is managing. Having a Client machine with a Netvault version installed upon it that is a higher version that that of it's Netvault Server is not supported.
If you have backs indexes from newer versions of netvault on clients in the database you will need to upgrade the netvault server to the netvault version of the client or greater, the backups indexes will be read and restore will be possible.