Uncooperative Loft

I am trying to create a loft, but i's not being the least bit cooperative. (I have better luck getting my 5-1/2 year old to put his pajamas on)..

Sometimes I get a nice general message saying that the loft failed to complete. But more often it says "Failed to reorder the guide curves" That message very rarely appears to be mentioned anywhere in the forums. What exactly does it mean?

HEre is a picture of my model: Profile curves are in blue, Guide Curves are in Purple.

Please also see the attached the file. It's in SW 2108, SP4.0.

This is a model from a few months ago that I'm rebuilding for another product family. I'm also using it to try other methods of modeling.

The items in the tree I'm working with are:

OUTLET TRANSITION EXT TAPER SIDE Sketch

OUTLET TRANSITION EXT FLANGE SIDE Sketch

OUTLET TRANSITION YZ GUIDE CURVE Sketch

Everything below that in the tree has been suppressed/ rolled back and still needs to be rebuilt.

I have tried doing the loft as a full solid and as a thin solid with various thicknesses (It needs 5/16" walls when all is said and done). I've even tried doing it as a surface.

For the inlet pipe earlier in the model, I also tried a loft, but it didn't work so ended up using a Boundary Surface. Here I need the loft because it has to follow the Guide Curves.

Thanks for taking a look and making suggestions.