Lightmap Shadow Issue (or maybe a Ghost?)

Hey Guys. Some new Pics for you. I`m running out of ideas now.

As you can see i have a House made of these small pieces. Now when i take the ones from the Unreal Engine (the walls with the windows) everything`s fine, but when i export them, reimport them, or change them, i get these weird shadow issues. As you can see i set up the light properly (i think its ok) and used the right Channel. I also watched the Vid from World of Leveldesign mentioned in another thread, but i cant get rid of this weirdness…

Can anyone help ?


Solved it on my own again… It`s an issue when trying to export a model from UE4 to Blender and Reimport. This process somehow messes up the lightmap. i recreated that piece of wall from scratch and importet it and had no more lightning problems…