BMW F06 rear-view camera flickers, vehicle indicates rear-view camera crash.

Hello together, I have had a BMW 640d Gran Coupe from 2012 for about 4 weeks. Unfortunately, the 6th shows me that my return camera would be disturbed, although I have the problem that it flickers continuously. Did anyone ever have this problem? And how can I solve this problem best? I am an absolute newcomer to a rear camera because I have never seen a car with a camera. Dear greetings and I thank you in advance for the answers.