The camera displays “This card cannot be used” when first turned on.
This error message that plagued me half the time I turned on my fancy new camera. I knew it was fake because removing and reinserting the card fixed it every time. Searching the internet did little to help me resolve this issue.
Finally, on page 212 of the manual I found an obscure comment about the Eye-Fi cards. It does NOT support endless memory mode. If you have this mode enabled you are likely to see the same problems I was having.
To resolve this issue,
simply disable Endless Memory mode from your computer and everything should be back to normal! Despite my best efforts I ended up sending the card back to EyeFi. They sent me a replacement in no time and everything has worked perfectly since then. Gotta give EyeFi a pat on the back for having great customer service. On the other hand, I’ll probably never buy another Nikon. Their service was terrible. Terrible.