I JUST got this error after using my 5 year old Sony F717 for an evening. I took quite a few photos, most in rapid succession. I had been using the nightshot feature, and had tunred off the shutter sound effect as this seems to actually speed up the cameras recycle time.
Suddenly it stopped working. I had 3 memory cards with me, and none of them would work with my camera. However, the cards still worked in my PSP. The data was visible when the PSP was connected to my computer.
After reading this forum (thanks to everyone who posted), and after trying several solutions with no success, I tried:
Pressing the card FIRMLY INTO THE SLOT, and TURNING THE CAMERA on while STILL HOLDING THE CARD IN AS FAR AS IT WOULD GO. I also gave a FIRM, WELL PLACED TAP WITH THE PALM OF MY HAND to the body of the camera.
I am not sure if it was the tap (or perhaps smack might be a better term) or the pressured insertion of the card. Regardless, the CAMERA WORKED immediately after.
I hope this helps to anyone else who has been able to confirm it is the camera, and not the cards. Thanks to all contributors.