Hello all, i'm new to this forum, and i hope you can help me

I made a simple test map for myself to experiment a bit with gtkradiant's functions. It's a room with on one site the human_reactor+human_spawn and on the other side alien_overmind and alien_spawn.
The room is fully closed and there is no hole or any open part to the Void.
If I look at my map info, I can see there is a 'worldspawn' but i don't understand what it is. Is it the place where you come in the map as a spectator?
If the 'worldspawn' is de problem in trem's error, what do i need to do, or how can i move/see the worldspawn?
Thanx allot. (my english is bad because i'm from the netherlands

)
btw. If it's needed, i can send you the .map or the .pk3