cups: Backend /usr/lib/cups/backend/usb does not exist! [solved]
it took me quite a while to figure this out so I thought I post this
here for someone else in need to find this.
I wanted to reinstall my printer Brother HL-3040CN after I upgraded to
stretch. That didn't work at first. The installer failed with "Backend
/usr/lib/cups/backend/usb does not exist!". ldadmin gave 'Bad device-uri
The solution was easy, if I had known what to do: copy
/usr/lib/cups/backend-available/usb to /usr/lib/cups/backend/. Doi!
Maybe this will help someone in the future.