https://web.canon.jp/imaging/eosd/firm-e/eos5dmk2/firmware.html
This firmware update (Version 2.0.8) incorporates the following changes and fixes.
Fixes a phenomenon in which movies are not taken at the shooting mode registered in the user's settings if a shooting mode Aperture priority (or Shutter priority) is registered in any of the camera's user settings (C1, C2, C3) and the user attempts to shoot a movie.
Fixes a phenomenon in which the shutter will not release when pressing the shutter button when the auto power off function is set to "on".
Fixes a phenomenon in which overexposure occurs when shooting a Live View shooting simulation with the ISO speed set to L.
Fixes a phenomenon in which the settings of the Speedlite transmitter ST-E2 revert to the default settings when both the camera and the ST-E2 are set to auto power off.
Fixes a phenomenon in which the Macro Ring Lite (MR-14EX, MT-24EX) and slave flash do not sync while shooting wirelessly.
The Version 2.0.8 firmware being released this time is for cameras with firmware up to Version 2.0.7. If the camera's firmware is already Version 2.0.8, it is not necessary to update the firmware.