I believe that error occurs when you install multiple mods that edit your FoC's data folder (C:\Program Files (x86)\LucasArts\Star Wars Empire at War Forces of Corruption\Data). That's why I tend to install them in a separate folder to see what they try to install, and from doing that I can tell you RaW and AotR both modify FoC's data folder. As such if you try to install both mods you will presumably mess your game up.