I am running macOS Sierra 10.12.1, which is the latest version of the Mac OS. I use the latest version of the AirPort Extreme router, and it is lightning fast and sends a strong signal throughout my house. I do not have any antivirus software installed on my laptop or desktop machines. I purchased an imageClass MF249dw and followed all the configuration instructions to the letter to connect it to the WiFi network because I want to be able to use the printer, copier, and scanner downstairs, without having to trek upstairs where my desktop computer is set up. I downloaded the drivers from Canon's website, which correctly recognized I am running macOS Sierra. I am able to print wirelessly, but I cannot scan documents from the machine to a folder on my MacBook or my iMac. The printer can "see" those machines on the network, so I can select them, but after going through all the steps to scan a document, the printer says "confirm destination," but does not allow me to select the computer to confirm. After a minute or so, the printer simply says "an error occurred" and allows me to close the window.
After many exchanges, Canon's email support staff have been unable to help me. They suggested I move the printer into the same room with the router to see if it is a problem with signal strength. That made signal strength go from "Normal" to "Good," but not to "Very Good," which appear to be the only three strengths in the Canon lexicon. It also did not fix the problem. I still cannot scan from the printer. That did, however, enable me to scan from the laptop using the MF Scan Utilitiy. However, it took 5 minutes to scan a 4 page document that resulted in a 4 MB PDF file. That suggests the machine, which has 256MB of on-board memory, is beaming the scanned data to the laptop after scanning each page, but it is moving the information at a snail's pace. Given that my phones and other mobile devices get 5 bars no matter where I am in the house, and given that my wireless router can move 4 MB in a few nanoseconds, this is especially troubling because a wireless multifunction printer is meaningless if it has to be located within a few feet of the router to get merely "Good" signal strength, and even then it takes 5 minutes to scan a 4-page document. That means scanning a 50-page document would take an hour or more!
I have lost faith in Canon's email support, and I will have to get up at 5:00 a.m. Pacific Time on a weekday to talk to their live support before work (Canon closes at 5:00 p.m. PST M-F, so anyone with a regular job cannot get Canon support.
I'm hoping someone in the community will take pity on me and offer to help resolve this issue.