SANE-compliant applications such as XSane and scanadf access the printer through SANE.
Make sure:
The scan driver is installed in the /usr/lib/sane directory.
The scan driver device file exists.
The scan driver is listed in the /etc/sane.d/dll.conf file.
“mfp_nscan” is listed in the /etc/sane.d/dll.conf file and no “#” is typed before it.
The SANE installation is using the directory structure /usr/lib/sane and /etc/sane.d/.
For some SANE installations, you may need to set the LD_LIBRARY_PATH:
On a terminal window, type the following, and then press Enter: