SD Card Cannot Be Found

Sony alpha ILCE-6000 does not read the SD card anymore. This is what I’ve tried so far:

• firmware upgrade
• formatting the card; erasing the files from the camera and then formatting the camera
• different SD card
• taking the battery off
• reset the camera

Nothing seems to help. The SD card stopped working suddenly, whenever I insert the card in the camera, the error message covers the display and cannot be made to go away.

Thanks