[V8i Ss4] Missing Corridor Outline Element

I have a file containing a Corridor that no longer is displaying its corridor outline element. I can select the corridor by some of its elements in the 2-D model but nothing is displayed. The Template Drop outline element is visible and can be manipulated to change its start and stop station. I can regenerate the corridor manually and get it to regenerate by manipulating some of its settings. However none of these create a new corridor outline.

The Level Manager reports there is 1 custom civil object on the level and the Element Selection tool can select the corridor by the level, but it is not visible.

This missing corridor boundary display appears to have manifested itself by causing the Superelevation file to become disconnected and attempts to reconnect generate a Power InRoads has stopped Working dialog box.

This file happens to be a copy of another file and both copies have lost their corridor outline and superelevation. One of my colleagues found he could only get the corridor to function by deleting it and recreating it.

Does anyone have any suggestions on repairing the corridor?