In almost all the canon EOS camera I’ve seen this problem . In almost all cases it is caused by bad care of the camera. A large amount of faults are caused by dirty cameras. Grease from fingers, small amounts os dust and dead skin building up until it failed. The solution above is correct. But care is the problem linked with cleanliness. Not only the specific area and fix above but also the seating area must be clean. This is to often ignored. As is each area on a camera where to surfaces meet such as the lense