problems editing a mod

hi i have this dawnofheroes mod and wanted to tweak it a bit. the download has the mod and source files.
i opened the playerlevels.dbr in the editor and changed playerlevel, ability points and skill points. then used build in asset manager to make it a normal mod again. everything works fine so far ingame but when i have chosen a class the window with skills is totally empty. i dont know what i have done wrong and need help. :confused: