I had the same "Processing, Please wait momentarily" error on my MX870 printer (on a system running Windows 10), and resetting/unplugging did nothing to fix it. However, Ramona's suggestion of scanning from Paint not only worked, but somehow "cured"...
Having encountered the dreaded B200 error code on my Canon MX922, I ran through the various proposed steps discussed here, including removing and cleaning the print head, and resetting the print head with the (print head) cover open. I still received...
