There’s a firmware update available for the EOS 6D Mark II. Firmware v.10.4 addresses a rare phenomenon where the touchscreen and camera buttons become unresponsive.
EOS 6D Mark II – firmware update v1.0.4
Firmware Version 1.0.4 incorporates the following fixes:
1. Corrects a phenomenon in which in rare instances, the operation buttons and some touch panel functions do not respond.
Firmware Version 1.0.4 is for cameras with firmware up to Version 1.0.3. If the camera’s firmware is already Version 1.0.4, it is not necessary to update the firmware.