Help with portals

It doesn’t seem to matter WHERE I put them, their always sealed off completely.
I always get errors about how it isn’t sealed off or how it isn’t touching 2 sides or something similar. The only time it works is if I have a simple room for a map and the portal going in the middle, and even then only one works.

This is really pissing me off, I read up on them and as far as I know I’m doing it right.

Can someone list the requirements etc

Do ensure this isn’t happening:
(The one on the left is bad, right is good.)

Also, make sure you’re compiling with VVis on full (you always gotta check these days :ohdear:)

Allright, I’m positive i sealed off the area but i was compiling fast. for testing reasons.

In short, just make sure there is no way to get from one side of the areaportal to the other side.
If it still gives an error, the load the pointfile, which should show you the problem.