Event ID 1023 appears in the Windows Application log when attempting to install a GPOADmin maintenance update.
The maintenance patch MSI installer fails because the MSI installer files for the GPOADmin base version were removed from their original location.
The behavior is expected because a maintenance is not a full installation. Normally, the original .MSI file is stored in the installer cache on the machine where the software was installed, and it is required for patching and uninstall operations.
If the installer cache has been cleared on the machine, the original .MSI package must be referenced.
Microsoft documents this behavior. For more details, refer to the following article:
See the fifth bullet point under Source Requirements When Patching for specific information on how .MSP patches work.
