I have a Color Imageclass mf644cdw on my local wifi. Worked great until recently where I cannot scan anymore with the wifi. What works:
So the problem is that when I launch the Canon MF Scan utility it says "
Cannot communicate with any of the scanners.
The scanners may not be connected, or may be turned off.
which is obviously not the issue.
In the MF Toolbox, there is no scanner and it says
No available scanner found.
If I try to add one giving the IP address it doesn't see any in Bonjour and putting the IP address says it's the wrong format (bug?). Not helpful.
The issue that you are describing looks like something is blocking the scanner connection or there is a network communication issue. You can try reinstalling the Scanner Driver & Utilities for Macintosh V2.15.10 from our support site using the link HERE. Once the scanner driver is installed, I would suggest unplugging your router from the power for 5 seconds and then plugging it back in. Once the network is back up, you can go into printers and scanners any you can try adding the MF644Cdw back to the list.
If you continue to have issues scanning after that, I would suggest contacting support at 1-800-652-2666. Our agents would be happy to check what problems are preventing the Mac and scanner from communicating.
I installed this driver (again as I had already done) but same symptom. Interestingly I have another Mac laptop (M1 as well) and it can scan with no issues on the same network which rules out the network issue.
I would like to try to uninstall the driver completely from the mac and reinstall it but I'm not sure how to do it clean like that.