Originally posted by clivebennett I too have just bought a practically unused (800 shutter count) K3. I'm having the exact same problem using 128gb cards, but these are micro-SDs with adapters. The micros have always failed after about 40 exposures; they are fine when downloaded to PC, but won't display on the K3 once they've failed. I've re-formatted and started again but the cycle is always the same. Odd.
This is the first time I've ever used these in a camera. I'm going to try the suggestion above and put in a straight SD 64gb and see how that goes.
I think it is the contact within the adapter which causes the problem.