Seems bizarre that having identified it didn't seem to be a valid route, rather than simply rejecting it, the system effectively switched off.
My best *guess* is that because flight plans can't be considered as completely independent of other flight plans, say C depends upon B completing and B intersects A, so you can't just bin a plan because you then have a gap in the state. That is a *guess* though.
It seems waypoint names are not unique and although those with the same names are usually some distance apart, it
This is an old, old, *ancient* problem. I have a John Smith, which John Smith am I dealing with? I know, I'll look at his customer/other *unique* reference number.
My next *guess* is that naming of waypoints is done on a country or regional basis without consultation with other countries/regions and there is no central body keeping tabs on waypoints. However a waypoint must have a lat/long and I would expect those to be unique so why waypoints weren't indentified in the code by lat/long rather than name does puzzle me. It seems the obvious thing to do.