External Lightmapping tool problem

I get this notice in the External Lightmapping Tool Window:

"This object will not get exported. It doesn't have any valid UV".

The object is an extruded spline with no UVs, which renders correctly in Unity. But I did add the UVW Unwrap modifier on the second channel for the lightmapping as shown in link text.

So my question is, besides the second UV map, is it required to have a UV Map in the 1st channel? (Maybe because of the shader??)

I didn't think it was required, however as a first attempt, I'd defenitely say: add a 1st channel uv map as well. I'll give you good odds that fixes it.

Yes, UVs in the 1st Channel are needed. Would be nice to be able to have this requirement removed, as some times you might want lighting without texture mapping.