Delete your original the small horse prologue in your custom stories file and replace it with this one then start a new game and it should work :)
This is a fixed version of the small horse prologue and it took me a while to get this one going so everything should be working now if there is any problems with the other small horse files please tell me and I`ll see what I can do for you all also you need winrar to open it up and also the file will be inside the file saying the small horse prologue fixed so make sure you copy the file and paste it just in case it did not work also do not start on a continue save cause it won't work that way so make sure you start a new game to get it to work :)
You fixed the invisible pyramid part? That part is still broken for me.