Recently, I had to return a GoPro 3 for a lockup problem. GoPro sent a brand new updated camera as a replacement (Thank You GOPro!)
The 32G SD Card recommended by GoPro was inserted, and on camera turn on, a SDCard Error message was shown in the camera front display. (Boo Hiss!)
The SD Card was previously formatted and checked in both windows 7 and 8 with a 32B Fat Format.
After all sorts of try this and that - -Sordid details skipped!
The camera did place an empty DCIM folder on the SDCard, as shown by windows.

The final cure!
Use the cameras wastebasket erase all function to properly setup the SDcard.

GOPro shows that this problem might occur with 64G SD cards, and recommends use of the 32G card to eliminate it!

No mention is made in the manual about the problem or the solution.
As of today, the GoPro website does not include the "cure" information in the SD related information.