Should the SCSI Request Sense Key error, or any other sub- system problem indicate that the library itself is in an invalid state for operation, you will need to execute a "Scan Elements" on the library to force the inventory process. (For Plasmon and IBM libraries)
This process is executed from the front panel of the library device itself, and must be done only when InveStore is not running. This causes the library to re-inventory itself, updating its internal record for the presence and location of media in both its drive(s) and its internal slots insuring a valid state.
Upon successful completion, the library will be in a valid state for operations again. If this should fail, you will need to contact your hardware vendor for assistance with servicing the device.