I bought my A7R2 2017.10.5, after two days' using, everything looks good, and I update the firmware to 4.0.0. However, the third night, when I was shotting, it suddently showed "No Card", so pulled out the SD card and put it in again, the problem still exists. So I tried serveral SD card, but the problem still exists. I gave up and decided to go to the Sony Support Service next day.
However, when I reached the Sony Support Service the next day, before I showed the camera to the stuff, it worked. And the stuff told me it's probably the wet or something, and I returned home.
But last night, when I turned on the camera, it showed "No Card" again, so I wonder it is the camera problem or the firmware problem, should I return it back?