I'm running grandMA3 onPC (v. 126.96.36.199) on a MacBook Pro (15-inch, 2017) with macOS Catalina (10.15.3).
When I connect my command wing, the grandMA3 Terminal says "Device attached". On command wing, the buttons Highlt/Solo/Freeze/Prvw/Blind are flashing.
Also, there are some errors in the grandMA3 Terminal when booting the application, such as "could not open file /Users/username/MALightingTechnology/gma3_1.0.0/system/config/Console.dat for reading"
Any others with the same problems? are there tested workarounds?