I doubt it's a version issue.
Have you checked that you don't have a double mod folder, like '/OXCE/user/mods/FMP/FMP/'?
Also, isn't FMP itself just a mod and not a 'master' mod? It is. So you enable it in the list, not from the dropdown? Could be wrong here.
If all else fails, take some screenshots of your mod directory tree and post 'em.