Cannot read my Memory card

Do not insert the memory cards when the in-use light is flashing. Doing so may cause data loss or permanent damage to the card.
Some memory card have a read/write or security switch, Ensure the switch is set to write enabled before you attempt to write data to the card.
Ensure the amount of data you are storing has not exceeded the storage limit of the memory card.
Ensure the memory card is fully inserted into the correct slot.
Inspect the ends of the memory card for dirt or material that closes a hole or spoils a metal contact. Clean the contacts with the lint-free cloth and a small amount of isopropyl alchol. Replace the memory card if necessary.
Memory card does not need Defrag.