I have tried multiple SDcards; used compressed air to clear card chamber; checked card for lock vs unlocked; and I still get the "card error" message. Before I take camera to a repair shop, I would like suggestions, please.
My only suggestion is to check the SD cards in a card reader. Logically your camera needs service or your SD cards are bad. It is easier to believe one device is bad rather than a whole bunch of them. But before you jump to the conclusion, testing the cards will let you know for sure.