Non-existent Staircase help

[Fear Everlasting]

I am very slowly creating a mod, and I have come to a little problem. I desire having an extremely long staircase ("symbolism" at its finest), and I have pieced the staircases together. However, when I test the game part of the staircase (and in turn part of the bottom floor) is non-existent in game, but shows up on my level designer. I have more then 14 staircase models pieced together. When I was originally fooling around when I started out with the level editor, I was able to make this staircase and play it in-game. I timed that staircase and it took over 30 seconds of running to get to the bottom, so it was quite a long staircase.

Yes I have saved my map, I even created a new save to load from and loaded from that save as well, with my stairs still missing. These saves have been correctly written due to a lever object I added during the stair making process. Does anyone have an idea as to what the problem is? If there is anything specific I need to upload such as screenshots or the map itself please post to do so.

Thanks for your time. I will respond as quickly as possible to any replies.