Pruning the forum database.
I followed the links, did some reading but not sure what all that means. I did install the sane backend
found USB scanner (vendor=0x04a9 [Canon], product=0x1749 [MG5200 series]) at libusb:001:002
it is not recognized by scanimage -L, and it is not yet in the device list (http://www.sane-project.org/sane-mfgs.html#Z-CANON).