When you upgrade the Endpoint Protection (SEP) client from version 12 to version 14, the install appears to complete, but you then get errors. After uninstalling, even using CleanWipe, you are unable to reinstall. The installation either hangs, or the service cannot be started after installation.
The installation package generated by the Endpoint Protection Manager (SEPM) may be corrupt. Files such as sylink.xml, setaid.ini, or other critical files may be missing from the installer package.
Re-generate the package from the SEPM.