First of all, i have had this problem over two phones and it is really frustrating.
The problem is that both cameras will not work and stay black or just open the app itself. The flash is also ruined and cannot be turned on. Evertime i try to use the flash a message saying that it is in use by another app come up. I had this problem on my samsung galaxy s7 and now on my new samsung galaxy s20 FE. This is a very concerning problem to me and i would appreciate any help.