Railworks America

The route previously worked fine, but now when I try to start it and make a scenario, the game crashes.
I have tried reinstalling it and clearing my cache, to no avail.

There are many people that have had your problem posted here on this site. Do a Search and see if that can help you. Suggestion is, first have you installed something recently that could cause this problem. IF no maybe you have corrupted a file in Railworks. You can run Logmate and post it's results here and maybe someone will help you.