This card does not work well ... I formatted my camera (Nikon 810) and stores very well ... (slow ...?) BUT, when I play and record the files on the computer, it asks me to FORMAT the card! and when it is formatted, it is my device I am asked to do the same! and so on ...! What can I do? Should I return it to you? Thank you for your response. Julio Penelas PS This is the first time I have such problems with a card ...