ZDoom

Fixed in r4141.

"Whoa man ... The whole level just turned into a pig ..."

*rubs his eyes and puts another tab on his tongue*

... at least there won't be an exploitation with a malformed wad for this case

What should happen would be ZDoom aborting with an error message along the lines of "Script 1 has performed an illegal operation and needs to be shutdown."

it seems you didn't see the zandronum tracker link ... that was obvious as a solution... but the crash shouldn't happen anyways.

Change your OPEN script into an ENTER and your script should at least work. Because I don't think you want to morph the entire map into a pig. (The OPEN script means that the activator is literally the opening of the map. By using an ENTER script, your activator then becomes the player(s) who actually enter the map.)

from http://zandronum.com/tracker/view.php?id=1279

ZDoom outright crashes if the following ACS is attempted: Example here. Just start a new game.