Help, my elevator makes my map corrupt.
Well, I don't know how you're doing it. If you are using the default instances, but they work perfectly for me... I would kindly recommend you to watch this tutorial:
http://www.youtube.com/watch?v=er5wplwYlHI
It is very clearly explained, I think you won't have any more problems.
If you still have some trouble, you may have your files corrupt. Try to check your files' cache: if there is any one in bad condition, you'll get new file automatically.
I hope that helps!
If that's not the problem, then post a vmf or screenshots so we can get a better idea.
I've always just assumed that you can't seal with any instance because the elevators always caused leaks.
I would say put a spawn point in the elevator. If you have done that, delete the instance file and verify Portal 2 authoring tools cache and it will redownload the instance.
Even though these are func_instances and they usually don't seal a map, it seems like these are special instances... any kind of exception or something.
BTW, Jure: if you have used those 5 instances (properly), you don't need to place any info_player_start or weapon_portalgun... player will be already spawn with a portalgun at the arrival elevator. Check out if that would be the problem...
Also, for your reference, msleeper already talked deeply about all this at:
Check out, it is very useful and interesting...