I am trying to create a loft between two triangles. One is a projected curve on the surface of a cylinder which has been converted to a 3dsketch and thus is not a true triangle. The other is just a triangle on a reference plane.

No matter what I have tried I cannot get it to resolve. I always get the zero thickness geometry error.

I have tried: 

Merge result on and off (although I need it to be merged as I am going to be 3d printing this part).

Changing the profile order.

Changing the triangle sketches from coincident with the surface of the cylinder to below the surface as well as out to the outer wall of the cylinder.

Adding another reference point to the curved triangle.

What am I missing? 

I am trying to create a shortened version of ridges that are on the other cylinder in this part (see attached part file). The reason I am approaching via lofts is because when I attempted to just do an extrude cut of an extruded triangle with a guide curve It also threw the ZTG error.

Thanks for any help.