Quote Originally Posted by malcolmlewis View Post
And your device is one listed in the udev rules file, you can see it present from the output of;

When you added the rule file, did you rebot, or run the command udevadm trigger and then plug in the device?
I tried it with and without the entry in the udev rules. It doesn't really matter since the printer is in another room. I've never connected it to a computer. I carry the .x3g file on an SD card.

This machine is an i7-4900K (Cannon Lake). It has Tumbleweed and Debian Buster installed. Older kernels don't work with the Cannon Lake peripherals.

Tumbleweed has Plasma 5.15.0 and Debian Buster has 5.14.5. Both exhibit the same behavior -- everything inside the window is blank. It works on Debian Stretch with Plasma 5.8.6, so I'm guessing that it's a KDE Plasma problem.