Anyone who has the wyvern and is using the release version of GameGuru, not the latest beta, will get a script error when using it. This is because it uses a function that isn't in the release version yet. I've attached a script that will work as a placeholder until GameGuru is updated. It will only work properly on the flat terrain you get with a new flat level, as it assumes a terrain height of 600, which is the default.
Sorry about the mess up!