A real-time example of an issue I’m experiencing right now is this.
I have some models in my level; when I build the lighting, I get a NULL StaticMesh property error.
All of my meshes actually have a mesh assigned to them. (I already rebuilt the LightMass project from the Engine source)
So, as I was suggested, I tried to clear that property and reset it (luckily there are just 6 models!!! what if they were hundreds???)
While I reset the mesh, this glitch happens in the Engine model-preview
AND LADIES AND GENTLEMEN
This is me when such things happen