What does it mean when a Canon camera displays the error message "Canon ERR 01" and how can it be resolved?

When a Canon camera shows the error message "Canon ERR 01," it typically indicates a communication issue between the camera and the lens. This can be caused by dirty lens contacts or a malfunctioning lens. To resolve this error, try cleaning the lens contacts with a soft cloth and reattaching the lens securely. If the issue persists, try using a different lens to see if the problem lies with the lens itself. If the error continues, it may be necessary to contact Canon customer support for further assistance.