Why does my camera not recognize an SD card?

It is possible that your hard drive cannot read the SD card that you have inserted into the camera, so you should try inserting a different SD card. If your camera does not recognize that SD card, it is possible that the SD card port is damaged in some way (most likely water damage), and needs to be replaced. It is also possible that your hard drive is malfunctioning and needs to be replaced. Finally, it is also possible that the software that reads the SD card is not working for some reason, and you should take your camera to a professional to have it looked at.