Running Big Sur on Mac Pro. Out of the blue, printer works fine (AirPrint mode), but when attempting to now scan, I receive the message: "Failed to open a connection to the device (-21345). Printer is recognized as default printer in Printers and Scanners and no errors appear. I cannot find anything online about this error now appearing. (Firewall is disabled as well.) Printer/Scanner is a TR 7020.
I, too, have this problem. I am on an iMac, running macOS Monterey, Version 12.2.1
My printer/scanner is a Maxify GX7020, and I have only just installed it. It prints fine.
But when I try to "Open Scanner" from the OS System Preferences "Printers & Scanners", it brings up a window that initially says "Waiting for scanner...", but then, after some time, says "Failed to open a connection to the device (-21345)"
I also tried using the Canon IJ Scan Utility Lite app, and click on the "Refresh Scanner Information". It already has a Canon G7000 series entry for another Canon printer we have, but it does not find the GX7020.
Please help! It would be nice to be able to use this scanner.
Disabling IPv6 on your MAXIFY GX7020 will resolve the scanning error (-21345) that you are experiencing. To do this, please follow the steps in this article:
Disabling IPv6 on your PIXMA TR7020 will resolve this issue. To do this, please follow the steps in this article: