Question to NextGen Maps/Models

[Felix-The-Ghost]

3XIX -- can't tell what you're looking at in your screenshots

While in edit mode type /fullbright 1 or place light entities so we can see

Are you correctly marking cubes as solids?

Solids and spaces
The reason we are covering solids and spaces, before moving cubes, is because solids block visibility and do not need to be rendered, so they are more efficient to use in maps. The use of solids in a map is essential to creating a good map. Without enough solids AssaultCube maps would lag too much for the average user and would be unplayable. Solids are also easy to create and can be used to make walls with a single keystroke!
Tip: When you've finished your map, change any unused space into solids.

• To make a cube into a solid wall, press F.
  
• To make a solid wall turn back into space, select it and press G.