The firmware for the UMO+ included with the Cura 3.6.0 release does not function properly on UMO+ the problem is that the controller screen becomes illegible i.e. becomes blue. I had to load a previous firmware from an older Cura version 15.04.06 to make it work.
Uh. That's weird. As far as I know, we haven't changed the firmware for the UMO+ in quite some time.