Welcome Patty… Sorry about that. I’m not familar with the pattern, but I’m sure @Grace will be along at some point to help you.
What it means is there is something in the measurements that is causing things to move where the line no longer intersects with the arc. And since the intersection point can’t be created the app has to use some point that is known. In this case we use the origin at 0,0. It’s kinda of like dividing by zero… if there is no point, the app crashes, and if the app crashes, you can’t load and fix the pattern without editing the xml file itself. Like I said @grace will be able to figure out what you need to do.