When you try to install Service Update 9.00 SP2, an error occurs: A newer patch update has already been installed on this CMS400 site.  The patch will now close...

The value of InstallVersion in Ektron.ASM.EktronServices40.exe.config is missing 0 in front of the .2. making the installer think it is a higher version.

1. Go to C:\Program Files (x86)\Ektron\EktronWindowsService40
2. Edit Ektron.ASM.EktronServices40.exe.config
3. Replace  <add key="InstallVersion" value="9.0.0.249.2.xxx" /> with  <add key="InstallVersion" value="9.0.0.249.02.000" />.
4. Save the file.
5. Install Service Update again.