Shows err on displaycant take picture

This message covers a wide range of problems and when it does appear, the camera locks up until you turn the camera on and off again. But this error indicates a problem(s) ranging from poor / dirty mating electrical contacts between camera body & lens (this inhibits communications between the two); to a shutter malfunction. It is pretty common for it to be dirty contacts on the lens mount opening on the camera body or on the lens itself. When this is the cause of the error, it is almost always fixed with a good deep cleaning. But it can also be more serious, so it doesn't hurt to contact Nikon if you are worried.

Try these suggestions from Nikon first:

• Remove all accessories from the camera.
• Install a freshly charged battery into the camera.
• If your Nikon camera offers resets such as the two-button reset or a hardware reset please follow those instructions provided in the product manual.