Hi John , were you able to get your network created with Pilou's advice?
Just in case I've attached here a modified version of your file which should now work with Network.
Basically that involved trimming the long outside curve so that it was in 2 pieces instead of all one long closed curve.
The way Network works, it needs to have a kind of grid layout of the curves that can be unwrapped down to a 2d pattern. It's pretty similar to how latitude and longitude lines on a globe unwrap to a flat map. When you have things coming to a point you need to have all the curves that come to that point end there, you don't want to have a couple of curves end there and other ones be longer.
Please see some of these previous discussions which have some more information and some illustrations about how the curve layout needs to be structured in order for it to work with the Network command:
