CASO, I loaded up Horseshoe curve to try this out as well. This is my first time running HSC on my new computer. When I tried loading any of the Career scenarios, I would get an instant crash. The same happened when I tried loading the route in the world editor.
I uninstalled the route in Steam by right clicking on the game in my library, then selecting properties, then unchecking the box next to the HSC route. I waited the 10 seconds or so it took to uninstall, then restarted Train Sim, and cleared the cache. Then restarted my computer, and reinstalled the HSC route via steam. Now the route and scenarios work fine, including the 'People Power' scenario, which I just ran through its completion.
I couldn't replicate the issue you had before with the route running up to a certain area, then crashing, but I can tell you that the fresh install from Steam works. I know its probably getting pedantic, but I would suggest reinstalling the route again, including clearing the cache and restarting as I described above.