Fujitsu 4120c - only some programs see it??

[GaryV]

Ok,

Strange problem I really need help to solve. I am running Mint 18.3, 64 bit, with the Nvidia graphics driver on an AMD A6 cpu.

I have a fujitsu 4120c scanner. Simple scan can scan from it (not duplex, though). VueScan and a web app I NEED to find it can not see it. The web app use Dynamsoft WebTwain to scan images from a web page interface.

I don't understand why Simple scan sees it, but nothing else does????

I have looked at the udev rule, and have tried several variants (commented out now), with and without the leading '0x' on the vendor id, posted below:

# FUjistu fi-4120c
ATTRS{idVendor}=="0x04c5", ATTRS{idProduct}=="1041", MODE="0660", GROUP="users"
#ATTRS{idVendor}=="04c5", ATTRS{idProduct}=="10ae", GROUP="users", MODE="0660"
# SUBSYSTEM=="usb", ATTR{idVendor}=="04c5", ATTR{idProduct}=="1041", GROUP="plugdev"

any help or suggestions would be VERY welcome.