Canon EOS 6D Mark II Instruction Manual page 562

Troubleshooting Guide
[###] is displayed.
If the number of images recorded on the card exceeds the number
the camera can display, [###] will be displayed.
In the viewfinder, the AF point display speed is slow.
In low temperatures, the display speed of the AF points may
become slower due to the AF point display device's (liquid crystal)
characteristics. The display speed will return to normal at room
temperature.
The LCD monitor does not display a clear image.
If the LCD monitor is dirty, use a soft cloth to clean it.
The LCD monitor display may seem slightly slow in low
temperatures or may look black in high temperatures. It will return
to normal at room temperature.
[Eye-Fi settings] does not appear.
[51: Eye-Fi settings] will appear only when an Eye-Fi card is
installed in the camera. If the Eye-Fi card has a write-protect
switch set to the LOCK position, you will not be able to check the
card's connection status or disable Eye-Fi transmission (p.522).
Image transfer with Eye-Fi card is not possible if [Enable] is set
for [Wi-Fi] in [Wi-Fi Settings] under [51:Wireless
Communication settings].
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