The port monitor requires administrative privileges to write system files (e.g., to C:\Windows\System32\spool\drivers\x64\3 ). If you run the installer as a standard user, the installation may be blocked silently.
By following the methods above—starting with and disabling antivirus —you will almost certainly resolve the error. In the rare case that nothing works, consider using Canon’s “UFR II” driver as an alternative, which uses a different port monitor architecture but still supports most MF functions. could not install canon mf port monitor exclusive