There is a new firmware for the Canon EOS-1D X Mark II. With the introduction of the manufacturer fixes the camera with SanDisk CFast cards.
Canon EOS-1D X Mark II made its debut in February, so as new equipment, still plagued him some problems. The camera did not cooperate properly with memory cards SanDisk CFast, resulting in some of the pictures were not saved correctly. New firmware 1.0.2 fixes a marked number on precisely this issue. Thanks to the camera will be able to work seamlessly with all memory cards, including SanDisk CFast. In addition, the new software does not introduce any new products, but we can expect that they will appear together with subsequent versions of the firmware. The software can be downloaded from the manufacturer . Source: Canon