Make sure the memory card is compatible with the camera. Please check the compatibility information in the instruction manual of your camera or the support website of your camera.
Purchasing a memory card from an authorized Sony dealer will ensure your card is genuine and compatible with your camera.
First try with removing the card and re-insert it into the camera again. If the memory card is still not detected at all by the camera, check if the contacts (metal part) of the memory card are clean. Sometimes dirt on the contacts causes connectivity problems. If some of the contacts on the cards are scratched and damaged, the camera will not be able to detect and use the card.
In certain cases it may be needed to format your memory card. Follow the steps below to proceed.
WARNING: There is a risk of data loss. When formatting a memory card, all the data on the card will be deleted.
IMPORTANT: When using your memory card with your camera, make sure it is formatted from the camera and not from a computer.
1. Open the menu, then go to setup menu.
2. Select Memory card tool.
3. Select "Format" and confirm.