Backup Exec 16 cannot restore from LTO-8

We are currently using Backup Exec 16 to save data to LTO-8 tapes using Quantum tape storage. We archived a data set which was split over two tapes, unfortunately one of the tapes was over written (the second tape). Presumably this is where the end of file resides which instructs the software on the data that is contained over the two tapes?

We have attempted to use the catalogue and inventory feature of Backup Exec to see if we can recover any of the data from tape 1. Unfortunately the catalogue feature fails and inventory doesn't return any results.

Is there anything you could suggest we could try to attempt to recover the data from tape 1?