The scanner works after adding the following to /lib/udev/rules.d/40-libsane.rules:
ATTRS{idVendor}=="04f9", ENV{libsane_matched}="yes"
The scanner works after adding the following to /lib/udev/ rules.d/ 40-libsane. rules:
ATTRS{idVendor} =="04f9" , ENV{libsane_ matched} ="yes"