I have been successfully using my D7100 since April This week I had two strange events where the shutter was clicking but no images were being stored. Those images were never seen again. Turning the camera off/on restored the ability to record images.
It seems like when the buffer fills (which was possible) that the camera is ceasing to recover? I was in the midst of shooting race finishers - bursts of 2-5 images. After a minimium of 10 minutes I resumed shooting and shot perhaps 30 images of the start of the next race - none of which were stored. Five minutes later when I noticed the problem I could not store a single image - until I powered the camera off/on.
I am using a 32 GB San Disk Extreme, freshly formatted in slot one - slot 2 empty. I have taken easily 2000 images on this card - formatting after each shoot - without a problem. I was using CH and CL settings.
I also have encountered this problem, twice. The camera would focus normally and take an exposure, just not write the new image to the card. I was taking single images, not a burst. After turning off the camera and removing then reinserting the card, the camera functioned normally.
I have since done the firmware update. I wonder if that will make any difference.
I had a similar problem. After shooting ~840 photos in that particular session (a high school sporting event) on a SanDisk Extreme 32GB SD card, subsequent photos would show up on the back of the camera when I shot them, but would not be accessible from the review mode and were apparently not being saved to the card. I swapped the two cards and continued shooting without problems, but lost about 100 photos before I discovered this.
I'm formatting the cards to see if this fixes the problem. I haven't yet tried to duplicate it.
I had my camera in for service and Nikon addressed the other item - no mentioned of this issue at all. I will do the firmware update and if I can isolate the issue I will report it here. In my experience a simple ON-OFF corrected the issue - other than the lost shots! That is where is feels like a software/electronics issue over a card issue but I can't prove it yet!