Yesterday (02/28/2022), after placing the XML files mentioned, on to a empty USB drive root directory. Plugged the usb drive into the USB Port on back of SMT-i6021 set. Enter Engineering Mode, Enter Administrator level, Go to “S/W Upgrade”, Change to USB, Start “Upgrade”. When upgrade is finished, set will restart. The software shows the “SPP-V01.40”. Now the SMT-i6021 will talk with the OfficeServ software. Thank all of you for your help with this issue.