While editing a path on the default Marias Pass route the path would end at what at first appeared to be a switch. Futher investigation showed that it was two dynamic tracks with the same start location.
The two dynamic tracks start at the point just south of the end of the path on the west track show in the first picture. The second picture is looking south from the west track at the point where the two dynamic tracks start.
Selecting these tracks resulted in the following messages:
Track database error: 'remove_end_end' one non-vector, one vector.
Adjacent track pieces not loaded. Can't select this track piece.
I was able to repair the track by removing the two dynamic tracks from the world file and track database and adjusting the two end points then adding one dynamic track to close the gap.
The track UiD, 3, and path point, 1, from the end node must match that of the connected track vector.
The dynamic track on the right in the second picture was defined as follows with three straight sections and no curves. This may have been the cause of the error as only the first section of this track would be drawn.