Upgrade to Symantec Endpoint Protection Manager (SEPM) 14 MP2 fails due to the side-by-side configuration error, the upgrade of the SEPM rolls back because it fails to install LiveUpdate properly.
In the log %TEMP%\SEPM_Inst.log the error message just before the line "Return value : 3" is something like:
Generate Activation Context failed for "C:\PROGRA~2\Symantec\LIVEUP~1\LUCOMS~1.EXE". Syntax error in manifest or policy file.
Component identity found in manifest does not match the identity of the component requested:
When you are trying to install LiveUpdate manually you may get the error "Install Error: 10, The LiveUpdate install failed because LiveUpdate was not able to register one of it's components. You need to have write access to the registry to install LiveUpdate"
The computer doesn't have the correct C++ runtime components installed for the system architecture.