Hi Everyone 
I have a problem with the fbx scenes imported to UE4. Just after import the scene looks pretty nice:
https://forums.unrealengine.com/filedata/fetch?filedataid=148146&type=thumb
…then I add some directional light to the scene and everything is ok:
https://forums.unrealengine.com/filedata/fetch?filedataid=148148&type=thumb
…but after building the light… a craziness happens!:
https://forums.unrealengine.com/filedata/fetch?filedataid=148147&type=thumb
it happens again and again! What do I make wrong? Thanks for any idea!