Editor Crash on changing Mesh Lightmap Index

I have converted a simple Brush (box, approx. 1800x1800x0) to a Static Mesh because I didn’t want collision for it.
At first I always got the following error on Lighting Build:* SM_Lake_Plane Object has wrapping UVs.*

The UVs look really crazy btw, but I don’t know how to fix them. I tried setting the Source Lightmap Index to 1, but the Editor crashes after applying changes.

Thanks in advance!

Lukas

EDIT: I’m not even shure whether this is a bug or just a mistake by me.

This is a known issue. It’s a bug that I reported several weeks ago. (UE-3102).

Thank you!

Tim

Thank you Tim!