Attempted to install a Feature Update from 1909 to 20H2 manually and got the error “Setup has failed to validate the product key” Saw that the machine had somehow lost its activation. Reactivated Windows manually via slui.exe 4 and phone call activation. Ran the 20H2 setup again and still got the error. Ran a sfc /scannow and no errors were found. Ran chkdsk C: and no errors found. Deleted all data in Temp folder. Ran the 20H2 setup again and still received the error.