I've also had the same problem and have tried a number of fixes. One worked temporarily until a Windows update caused the problem to recur.
I've just used revo uninstaller (free and safe) to delete all traces of MF toolbox and drivers. I then reinstalled everything from the Canon website (drivers for MF4150 and MF toolbox 4.9).
Everything seems to work. Print and scan.
Too early to tell if next automatic Windows 10 update causes a problem.