Making Skeletal Mesh lods in Blender issue


I am trying to make lods for skeletal meshes. I can export the skeletal mesh, import it into blender and decimate. But having problems to export the changes right way into fbx so importing lod in ue4 editor wouldnt fail. As strange thing I managed once succesfully to import the new skeletal mesh lod for FPS weapon pack weapon, but cant do it anymore. Even if loading the fbx in blender and exporting without doing any changes makes the fbx incompatible to be lod for the orginal skeletal mesh.

Using these steps:

For static meshes all goes good. But quite lost why the skeletal mesh lods fail even it worked already once. :S

Using blender 2.76, saving fbx files to desktop.

Edit: Nevermind, got it finally working. Didnt realize how the export options worked until after hours of brain farting. The above link guidance work very good. Also left add leaf bones off, and in animation toggled force start off and key all bones enabled.