

I think it is not digitally signed problem because I try the above step to disable it.

Put Windows in test mode (bcdeit /set testsigning off).Disable driver signing code on "Local Group Policy" (User Configuration > Administrative Templates > System > Driver Installation > Code signing for device drivers entry > Enabled - Ignore).Start up the windows from "Disable driver signature enforcement" mode.Download the latest driver from Vendor (release on May-2021) and update manually.For details, see 'Encrypting Network Communication', User Guide. Install the device certificate before using 'MFP Address Book Downloader'. I try the below solution but the problem is still here : Use 'MFP Address Book Downloader' and 'Address Book' in 'LAN-Fax Generic Utilities' to import the address book registered to the machine into the 'Address list' of the LAN-Fax driver. It show "The driver cannot be installed because it is either not digitally signed or not signed in the appropriate manner. I also try to update the driver on this printer but it is not work.

I open the "Device Manger" and check the driver. The Windows can't install the network printers which is through "Group Policy" to install. I have a problem after update the Windows 10 from 1803 to 20H2
