The site maintains a strict policy of only having content that is of value to the public in some way. Content should be thoroughly worked on before submission, and a node will be deleted if something remains seriously wrong with it for a long period of time.
If this is a map, it could mean a problem with the lighting, texturing, geometry, or layout; try the Cube Wiki for tips on using the engine. Should it be some other form of content, then it may need to be elaborated upon to be worth something.
The layout of a map is among the most important parts of a winning design, try making sure exotic geometry is removed or clipped and the level is open and free of dead-ends or unexplained phenomena.
Refer to the Packaging Guide for information on how to fix this.
This is a large map that I made, it includes many buildings in a compound including several bunkers, barracks, and a factory, surrounded by walls. it also has a very large network of tunnels between the buildings. there are many neat features like secret rooms and hiding places. This map is almost done, but I might add some custom map models soon. It has bot waypoints included.