The library canno't found empty tapes

Hi,

I'm managing a Backup Exec 2012 SP3 console over a windows server 2008 R2 Entreprise ed. 

The issue is when i send a job, the drive seek a empty tape, but say isn't available, please import etc... however i have on or more tapes in the correct partition and the right properties. The job can start with a tape, but if need a second tape, again is the same problem.

Help me, i have two libraries with the same error.

Thanks.