Game Input MultipleXer

Lately I've been figuring my ways through achieve the sweet spot of dead zone and sensivity, but I can't really get the calibration to work. When I 'tick' the calibrate button and press start, it just doesn't show any info in the box:

As you can see it doesn't really display what my mouse is etc. and it doesn't know any of the values at all.

Did you tried to press rctrl+F1?

Yes, nothing changed.

EDIT: I've also tried with different configs, and trying to run emuclient.exe while having the gimx-serial running in the background. It just pops up a split second and closes down. In those 100 milliseconds of display it seems to say something like: "No serial port specified".