I saw a post about uninstalling Cannon drivers and software and re-install to fix but this didn't work for me. I have Windows 11 and am connected to the printer wirelessly.
I go to the printer and press scan, then remote scanner. Then I go to the Canon MF Toolbox 4.9, the window is greyed out, there is an empty oval above all of the utilities. When I click on the Settings button, the scanner is there (Canon MF 4800 ser_etc), along with Computer Name, etc. I then click OK and the MF Toolbox is correct. But then when I click on PDF I get the following error:
Cannot communicate with the scanner.
The cable may be disconnected, or the scanner may be turned off.
