I need help with this one. I can't start the map up again, because it doesn't show up on the map list. How do I start it up again?
With that your map should be working. If both folders are identical, I suggest removing the .zip while you work on your map.
Note: If you keep both the .zip and folder in your add-ons folder, whenever you work on your map, save it, and restart the map again, the map will be like you hadn't worked on it the last time (because it executes the .zip but you saved it to the folder).
Also, I'm getting a less important glitch. When I approach terrain with my sand texture, it turns back to the Flatlands grass texture when I'm close enough. How can this be fixed?
Relight the scene? That shouldn't happen after the scene has been relighted.