Camera not working at all - crashes on opening

Pls help me.... Both the front and back camera of my HTC one M8 eye is not working for weeks now.... I have tried all the options posted here and nothing seems to work...... Pleaseeeeeeee HELPPPPPPPPP........
 
Hi everyone so I recently replaced the battery in my HTC M7 and when I turned it on the Camera did not work anymore all I get is the black screen about three seconds and then it goes back to the home screen I've done everything that everyone has suggested from factory reboot to recovery to delete cache to going to safe mode or you name it I've done it what is the next step I don't really want to buy a camera because I don't think it's broke but if that's one suggestion I may have to do that