Insufficient online or nearline media is available to start job

Hi,

I am trying to set up a backup on a tape library DELL TL1000.

I created a backup job but when I tried a test run I get the following error message:

Media CheckOnline media check : Insufficient online or nearline media is available to start job.
Overwrite media check: There is no media online or nearline that can be overwritten or the job has been marked append/terminate.
Media check status : Failed

If I try to run now the job status goes in Active: Queued and it keeps it's status on queued forever.

I have already check others post similar with issue similar to mine but with no success, like this for example:

Insufficient online or nearline media is available... - VOX (veritas.com)

Attached some screenshot.