After an advice of VEEAM SUPPORT, I upgrade Veeam Backup & Replication from v7 to v8, I installed the v8 Update 3 too.
But my tape library became offline:
- I checked the device manager, the library and drives appears
- I checked the services, OK
- I restarted many times, the library is offline
I click on "Rescan", a new library with the same name appears, without my media pools, but a media poll called "Imported" was created with all my tapes in it.