Can't "recalculate" route


I downloaded a GPX file for a "route" from a local website.

When I import it into Basecamp's "My Collection", it displays a list of waypoints, a "route", and "tracks".

The route displays all the waypoints, with straight lines between them, which can be normal prior to any recalculation.

When I "open" the route, all the points are listed however when I attempt to "Recalculate" (which will typically replace the straight lines with a proper calculated route between the waypoints), no route is created and I still have the straight lines between points.  Also, when I view "Route Directions" is simply lists the waypoints and no turn-by-turn information.

I can't properly display the route in Basecamp.

I don't know what application was used to create the GPX file but it seems some key data is missing.

Anyone have thoughts on what is missing?