Sorry for the long post, but this has happened to me. Maybe my experience can help you a little.
Elizabeth gave you good advice about the battery, but wait a few minutes before putting it back in, like when you turn a computer off and back on again to get it working. If the battery wasn't fully charged, charge it and try again. If it doesn't hold a charge like it used to, you need a new one.
If the camera doesn't sound right, something's probably broken. You might have dropped it or banged it up against something and not even remember. If anyone else used it talk to them, but don't assume they broke it. They may just have been unlucky enough to be using it when something went wrong.
The error might not even be related to the lens. I got a shutter error once, but the shutter was fine. The camera's computer had gone bad and needed to be replaced.
If the Coolpix is still under warranty, send it back to Nikon. If you got it somewhere like Best Buy and bought an extended warranty that's still in effect, take it there. If it's out of warranty it will cost about $50 to get it checked out. If it cost under $300, it's probably not worth fixing.
If you need to replace it, you don't have to buy new. B&H always has used and refurbished Nikons, starting under $100 for Coolpixes and going up to $5,000+ for a D4 body. Right now, they have 16 refurbished Coolpixes from $50 to $400. If you buy one and there's a problem, they accept returns. You just request an RMA. When you get it, just pack it up and send it back.
