The object wich wasnt showing up is made by me, made of basiccube.mesh and basiccone.mesh retextured.
For me, it worked perfectly fine and how I found out for a friend too. Just for my other friend...
Anyways, the map won't let me in again (FeralHeart.exe has stopped working-message) and I can't re-export it since I lost it like mentioned before
I think I'll just have to accustom to the fact the map is lost.