Error while creating backup on DAT (tape drive)

Hello All,

I get the following error messages when I try to backup (task) about 40 GB of data on a tape drive.
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Following the error log:
Fehler beim Schreiben der Datei. (0x40003)
Tag = 0xC41DEFBA28F4D130
Kein Medium im Laufwerk (0xFFF0)
code = 80070458)
Tag = 0xBD28FDBD64EDB8AF: Wiederholen/Ignorieren/Abbrechen
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I hope someone can help?!

Best regards!