Fixed by running Ink Flush in the Maintenance menu. I've been having the same problem as you, updated firmware, reinstalled software, tried cleaning and deep cleaning a few times, nothing. Just now, however, I did an ink flush. That solved my problem...
I followed the directsions of Piers_A on page 3 of this thread (http://community.usa.canon.com/t5/Office-Printers/MF-Toolbox-doesn-t-work-on-Windows-10/td-p/147893/page/3#). It is quick, easy, and it worked fine as soon as I rebooted. My MF4450 scan...
