...
Programming the application into the MMU Control Board (on Linux):
If you have the modemmanager installed, you either need to deinstall it, or blacklist the Prusa Research USB devices:
/etc/udev/rules.d/99-mm.rules
# Original Prusa i3 MK3 Multi Material 2.0 upgrade
ATTRS{idVendor}=="2c99", ATTRS{idProduct}=="0003", ENV{ID_MM_DEVICE_IGNORE}="1"
ATTRS{idVendor}=="2c99", ATTRS{idProduct}=="0004", ENV{ID_MM_DEVICE_IGNORE}="1"
$ sudo udevadm control --reload-rules
A request has been sent to Ubuntu, Debian and ModemManager to blacklist the whole Prusa Research VID space.
https://bugs.launchpad.net/ubuntu/+source/modemmanager/+bug/1781975
https://bugs.debian.org/cgi-bin/pkgreport.cgi?dist=unstable;package=modemmanager