Canon has issued a firmware update for the EOS 5D Mark IV camera to correct a problem when using flash and improve performance with the latest teleconverters.
Firmware version 1.0.3 corrects a problem that created different colour temperatures with flash output depending on which metering mode was selected. It also improves communication between the camera and the lens when the new EF1.4x III and EF2x III tele-converters are in use. Another improvements provided by the new firmware is correction of the level display when the camera is held vertically with the hand grip pointing downward. USB communication has also been made more reliable when using the Lens Data Registration function with EOS Utility 3.
Firmware Version 1.0.3 is for cameras with firmware Version 1.0.2 or earlier. The new firmware is available to download at https://www.canon.com.au/cameras/eos-5d-mark-iv/support?option=drivers.