Canon EOS 6D Mark II Function Instruction Manual page 149

122: Connect to a computer, and correct the settings for
the Web service with EOS software.
Web service setting operation may have failed.

Connect the camera and computer via Wi-Fi or with an interface

cable (sold separately) and reconfigure Web service settings using
EOS Utility (p.95).
123: Cannot log in to Web service. Connect to a computer
and correct the settings with EOS software.
Is the camera's registration information or Web service

registered on the camera deleted on CANON iMAGE GATEWAY?
Connect the camera and computer via Wi-Fi or with an interface

cable (sold separately) and reconfigure Web service settings using
EOS Utility (p.95).
124: Invalid SSL certificate. Connect to a computer and
correct the settings with EOS software.
The root certificate has expired or is invalid.

Connect the camera and computer via Wi-Fi or with an interface

cable (sold separately) and reconfigure Web service settings using
EOS Utility (p.95).
 This error may be displayed if the camera's time setting is
significantly off from the actual time. Check if the correct time is set
on the camera.
125: Check the network settings
Is the network connected?

 Check the connection status of the network.
126: Could not connect to server
CANON iMAGE GATEWAY is under maintenance or load is

concentrated temporarily.
Try connecting to the Web service again later.

Responding to Error Messages
149