UNSOLVED Black Desktop after installing PIR-Sensor

[Klinge]

Hello,

unfortunately I have a problem with my PIR-Sensor.
I followed the instructions of MagicMirrorCentral (https://www.magicmirrorcentral.com/pir-sensor-raspberry-pi-magic-mirror/).
Now the PIR sensor also works. But after I installed that and restarted the Raspi, my desktop is black. But only the desktop. The application, MagicMirror, is displayed. When I minimize MM with Ctrl + M, I only see a black desktop. The mouse pointer is displayed and can be moved. But I can not click on anything.

Of course I already tried the option with “vcgencmd display_power 1”. Unfortunately with the same result.
I would really appreciate, if you could help me.

Thank you in advance.
Lars