I have tried 2 memory card in my camera and both times I get the on screen message, "Memory Card Error". When I turn the camera to play mode I get the Error and a message that says "Card Locked". I have tried using the slider on the side of the card with no luck. I have also tried to format the card on the camera but this option is grayed out of the menu... thoughts?
That's a tough one, I would try the card in another camera/computer to see if it works. If the cards are good then maybe it is the contacts between camera-card. Try putting a card in/out a lot to try to knock off anything that might be getting in the way. Perhaps a pin is bent? Another idea is that the camera thinks that the card cover (which you may have to open or slide to access the card) is not closed, check to see that a switch is functional so that the camera knows the cover is closed.
That's all I can think of unless your camera is just at the end of its life. Hope that helps!
Trying Your memory card in other camera may give you idea that where is the actual problem it can be with your camera also. If you have some important pictures in your memory card then your try it with a card reader in your PC, if you are still not able to access your card then format your card and try photo recovery software to recovery all your data from memory card.