Railworks America

So my friend and I are working on a route together, and I just recently had the infamous glitch where the terrain for a couple "chunks" will snap back to 0 height and leave tracks, roads, and scenery floating in the sky. It doesn't seem to be the whole route, however.

Any thoughts?

If you have a backup which I'm sure you do if two of you are working on something find those tile numbers and replace them with your backup. See if that fixes it. If you need more specifics holler.

This has happened a few times to me, and clearing the cache and restarting was all it took to fix it.

Otherwise, Buzz's method will certainly work.