My camera has stopped working on my nexus 6, Android 7

The camera app acts like it wants to start, but will not. Not only has my camera stopped working, my flashlight has disappeared. I installed other flashlight apps, but none of them work. In the camera app I forced stop, cleared data and cash. Didn't help. I also have Avast anti virus which is always wanting to remove excess files. I don't remove anything using Avast.