I upgraded 17.10 to 18.04 and the problem remains the same :-(. I also did a new installation of 18.04 from scratch and that one isn't working either.
I did find, however, a workaround (for 17.10 and 18.04). If I set
export SANE_USB_WORKAROUND=1
in a shell and start a scan application afterwards like gscan2pdf or simple-scan, than scanning works using both applications. Some changes made since 16.04 in the sane framework seem to have broken support for the scanner part of my MFC. You should try setting the variable in the shell an see if it also fixes your problem.
I upgraded 17.10 to 18.04 and the problem remains the same :-(. I also did a new installation of 18.04 from scratch and that one isn't working either.
I did find, however, a workaround (for 17.10 and 18.04). If I set
export SANE_USB_ WORKAROUND= 1
in a shell and start a scan application afterwards like gscan2pdf or simple-scan, than scanning works using both applications. Some changes made since 16.04 in the sane framework seem to have broken support for the scanner part of my MFC. You should try setting the variable in the shell an see if it also fixes your problem.