The MF634cdw printer drivers work correctly under both Win 10 and Win 11. However, while the scanner utility winmfscanutilityv12102.exe works correctly under Win 10, the utility does not work under Win 11. The error message reads, in part, "Cannot communicate with the scanner...."
The multifunction unit is set-up to communicate over the LAN. It appears that there is a bug in the scanner utility.
