The SPECTRUM upgraded failed with SPC-INT-20031 error using the local administration service account to do the install (screenshot).
The owner parameter in the $SPECROOT/.installrc was set to a local admin user that no longer existed. This was the cause of the failure.
Release : DX NetOps Spectrum 20.2
Component : INSTALL AND SETUP
Open the $SPECROOT/.installrc file on the SpectroSERVER
Change the "OWNER" parameter to a valid local administrator user, save the file and start the install.