How do i use a weightmap or splat map to creating my master material in ue4?

im using world creator and i dont find in depth guides to using the weightmaps or splatmap in the material for your landscape. im pretty new and i tried the method mentioned in the texturing tutorial for world creator using layer colors and importing the heatmap but i get messages like this and it looks really weird and messed up. ill post pictures. they dont really show how to use the splat map either. if some one can be kind enough to help.