Hi @jamie.q.white,
Sorry to hear that this is happening to you! I went ahead and created a Screencast that details my steps and how I went about making this sketch work. I think that the error has to do with where your cradle sketch was created. If you go ahead and edit the Profile Sketch for the Cradle component you notice that it will move your screen to where the spline ends up which is really odd. Did you do a move function on the sketch perhaps? My fix was to project that sketch geometry into the current sketch plane so that its coordinates would be correct again. I will look into why that is happening, but in the meantime at least you have a fix! Let me know if this worked for you or if you have any other questions. Check out the screencast below!
Thanks,
James Youmatz
Product Insights Specialist for Fusion 360, Simulation, Generative Design