Hello,
I got and replied to your email, but I'll reply here too with a short answer: the camera gameobjects in this scene have a component that's no longer included in Unity. (GUI Layer) If you remove the component the scene should build fine. (Other sample scenes probably have this component that needs to be removed, too) STM doesn't use this component at all, and I'll make sure to remove it in the next build I upload.
Thank you!
-Kai