With both cards in follow instructions on page 32 or 236 of the manual. If that doesn't work, try removing both cards and then put 1 card in slot one to see if you can format the card and then do the same for the other card in slot 2. Check your manual pages 85 and particularly 86 regarding setting the image quality for slot 1. Hopefully, this will help unless there is a problem with the cards or low battery. Good luck.
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