I have quite a few props that I have made as a Group in XLights.
For example I have 33 minitrees. I have put them in a group called Minitrees. When I do an effect on the group it works beautifully, however when I try to export to LOR nothing comes out. I have had a play around and it seems that goes with ALL groups. So again, I have 9 pixel steps in a group called Steps. I put pattern on group, works well in XL, cant export to LOR.
All of my "complicated" props where I have have to split the model drawing over the whole house are also in groups. So e.g house outline is a group. Xlights great, but cant export to LOR.