Canon has released firmware update 1.0.4 for the EOS 6D Mark II, adding important bug fixes for “rare instances” of issues with the touch panel and operation buttons. The update, which is available from Canon’s support website here, is about 30MB in size and includes the following changelog:
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.
via DP Review