Plat ed starts off as 1.4 patch
which means any 1.4-incompatible mods will not run (all it does is take you to loading screen and then exit program OR freeze OR crash)
Also you go into the part off the main menu called "Mod Manager" or "Add Ons" or something like that, near the bottom of the list.
Inside is all the mods you have installed, select one hit activate and voila |