the main problem is, that:
„I still get no video output even for sandard Max2play interface – screen is just blank
I get a similar error message when trying to start Kodi (as shown below)“
this is why Kodi is not able to show anything on the screen (as stated in the error message on start up).
How to fix: Make sure to connect the HDMI-Cable on startup of the XU4 and turn on TV/monitor. Make sure to use a quality HDMI-cable. Some thin cables may not work…
Hope this helps!