i mean like i follow the tutorial from http://www.cs-maps.jolt.co.uk/index.php?page=skies.htm but still i cant see the sky. it show blue only. why is that?

what is "The solid has invalid structure, probably as a result of vertex manipulation."

how bout sky? how to made it? i try to follow d instruction. but still cant follow it

thanks already done. and one thing, where can i download prefab? i need somekind of building oor whatever. thanks

den how to make a door? i mean rotating door

title said so