Open Edges Error

[Glitcherguy]

everytime i make a hole in my map (for doors and windows) this error shows when i try to create scenery:
Couldn't read map file './toolbeta.map'
building intermediate geometry...
building collision geometry...
### ERROR edge #222 is open (red).
### ERROR edge #532 is open (red).
### ERROR edge #789 is open (red).
### ERROR edge #866 is open (red).
### ERROR edge #933 is open (red).
### ERROR edge #1732 is open (red).
### ERROR edge #1736 is open (red).
### ERROR edge #2141 is open (red).
### ERROR edge #2146 is open (red).
### ERROR edge #2149 is open (red).
### ERROR edge #2152 is open (red).
### ERROR edge #2161 is open (red).
### ERROR edge #2164 is open (red).
### ERROR edge #2169 is open (red).
### ERROR edge #2174 is open (red).
### ERROR edge #3752 is open (red).
### ERROR edge #3756 is open (red).
### ERROR edge #3973 is open (red).
### ERROR edge #4446 is open (red).
### ERROR edge #4449 is open (red).
### ERROR edge #4451 is open (red).
### ERROR edge #4453 is open (red).
### ERROR edge #4459 is open (red).
### ERROR edge #4460 is open (red).
### ERROR edge #4475 is open (red).
### ERROR edge #4477 is open (red).
### ERROR edge #4485 is open (red).
### ERROR edge #4488 is open (red).
### ERROR edge #4491 is open (red).
### ERROR edge #4494 is open (red).
### ERROR edge #4501 is open (red).
### ERROR edge #4505 is open (red).
### ERROR edge #4507 is open (red).
### ERROR edge #4512 is open (red).
### ERROR edge #4515 is open (red).
### ERROR edge #4519 is open (red).
### ERROR edge #4521 is open (red).
### ERROR edge #4524 is open (red).
### ERROR edge #4527 is open (red).
### ERROR edge #4535 is open (red).
### ERROR edge #4541 is open (red).
### ERROR edge #4543 is open (red).
### ERROR edge #4545 is open (red).
### ERROR edge #4548 is open (red).
### ERROR edge #4552 is open (red).

I make holes by deleting faces, but i guess thats wrong cause it never works. I tried to import wrl, but i did'nt know how to fix it

[Patrickh]

yeah, don't do that... make sure your map is sealed