Hi fatcat19600.
I will be able to assist you.
Ii is recommended that you update the printer firmware. The firmware update can be downloaded from the Canon website. Please click the link below, and then click the [Firmware] tab to select the update:
imageCLASS MF726Cdw - Drivers & Downloads
Should you still experience an issue with the [Copy] function, please call us at 1-800-OK-CANON (1-800-652-2666).