Object has wrapping UV's error

I get that error message when I build my scene after I made a custom mesh. I’ve been trying to figure out what’s wrong and I can’t seem to figure out how to generate UV’s.


Open mesh in Mesh Editor and check next parameters:

  1. Mesh need contain UV1 for Lightmaps. If not, export to 3D programm and add secondary UV.

  2. Light Map Coordinate Index should be set to 1.

  3. If you have not change Lightmap Resolution after creation, try set a different value.

why i cant change light map coordinate index?

why i cant change the light map coordinate index?