Meshing errors

I just stated using COMSOL and I'm trying to build two helical coils stacked on top of each other with a ~5cm gap. Whenever I attempt to build the mesh I get the error tree,

failed to generate mesh for face>> failed to insert point >> empty cavity created.

I also receive several geometric boundary sections.

I've read about creating a sweep mesh but I keep receiving an "inverted element `" error.

I've attached the .mph file to illustrate the issue