I'm afraid we'll need a bit more information to stand a chance of fixing this. If you can post again and tell us what your device is and describe the problem in more detail (does it force close when you open the camera app, or fail to store pictures, not respond to controls, or ...?), when did this start and had anything changed before then (software updates etc)?
Don't worry about giving too much detail, as anything may provide the clue which lets someone identify the solution.