Wrong Medium Type
You put a floppy disk into your CD-ROM drive.
Seriously, this error means that a device driver couldn't understand the currently connected media. For example, you have tried to mount an audio CD as a data disc, or alternatively tried to listen to a data disc as a music disc.
The linux kernel also uses this the atmtcp network driver, and in some tape and disk drivers when running on the IBM s390 architecture.
No page links to EMEDIUMTYPE.
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