I need help!

[Statyk]

Open your "resources.cfg" in your root folder using Notepad or Notepad++ and add a directory leading to the folder that holds this model.

The reason it is doing this is because you originally loaded the models in the level editor, so they show up, but when you go to run your level editor again, it reads through the directories in the resources.cfg and if the folder that this model is in, is NOT in any of the directories listed, it won't load. So you have to add a directory.