I have not added a new path to this route since 2011, so whatever path(s) is/are causing a problem now was in the route before I edited the route a few days ago. I would suspect that most anyone creating activities will have some broken paths, missing paths, etc. in a given route. If those cause TSRE to crash, then I consider that a bug in the program. Ideally, the program should error trap the problem paths, etc. and report them, but not crash. I have not had a problem with any other routes crashing TSRE in prior versions of the program, even though I know that some of them have missing or broken paths in the Paths folder.
I believe this is another reason that the AE and Route Editor functions should be separated. When the user wishes to edit the route itself, there should be no reason for the program to concern itself with paths, services, traffic, etc. Conversely, the only reason that I can think of that allowing the AE to edit a route would be if a provision was made that route objects could be added to appear in a specific activity--for example, adding clutter (people, equipment, etc.) to a scene specific to activity (this is one of the relatively few features that Train Simulator 20XX has that MSTS/OR does not).
A zip file of the paths is attached. Thanks.