Canon EOS REBEL T7i Instruction Manual page 449

[###] is displayed.
If the number of images recorded on the card exceeds the number the

camera can display, [###] will be displayed (p.343).
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 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.

In low or high temperatures, the LCD monitor display may seem slow

or may look black. It will return to normal at room temperature.
[Eye-Fi settings] does not appear.
[Eye-Fi settings] will appear only when an Eye-Fi card is inserted 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.414).
If [Wi-Fi] is set to [Enable] for [Wi-Fi settings] under [51: Wireless

communication settings], [Eye-Fi settings] cannot be selected even
when an Eye-Fi card is installed.
Troubleshooting Guide
449