TAK Webserver setup for Event.

I am struggling with the setup of the webserver based application of TAK (Team Awareness Kit). Even after installing the server as shown in the tutorial on the official website it doesn´t start. If anyone could help me with it. The problem lies within the certification files in the Core Config, but everything I've tried doesn´t help. I already started over several times. I don´t seam to find the real problem.