Pixhawk crashes

Hi, I am new to the Forum and I have a problem, that I can´t figure out. I have flashed the latest px4 firnware onto the pixhawk with the I2C Lidar driver enabled, otherwise nothing changed.
It boots up fine and connects to qgroundcontrol, but after a while (usually a few minutes) it crashes. The pixhawk stops sending data over telemetry, flight modes don´t work (only Manual), I can´t arm and the blue IO LED starts flashing rapidly and the red IO led flashing slower, about 2hz (see Video: https://youtu.be/KTBSOSc5GKQ).
I have tried googleing, but didn´t find anyone else having this Problem. I tried changing SD Cards, also no Change.
Any help would be appreciated.

The problem seems to go away if I mount the telemtry module further away from the pixhawk. Did anyone else experience this?