Hi there and welcome
I can read what you are typing in German but can answer you in English, is this ok? If so we can continue here
Please let me know.
This is usually a sign of dust in the Laptop, it builds up in the laptop and causes it to overhear.
Can you power off the Laptop and remove the power cable.
Then vacuum out the dust via the air vents, then turn it on and tell me if you still get the error please.