Originally Posted by
YourMaster
There's very little you can do about it. Path-finding is units determining a route from place A to B on the map. When you've got maps with many possible routes, especially when they cross water/lava multiple times, the game will freeze. Sometimes you get warned by slowdowns or units not finding stuff they should be able to find just fine (like imps not finding the way back to the treasure room), but sometimes the game will just freeze without warning.
This bug was already in the original game, and the original maps are mostly save. In some levels you might get into trouble in rare situations if the AI Keepers build too large and complex dungeons, or if you do the same, the solution would be to play to win, not to continue indefinitely. Several custom maps you can download do suffer from it though, and it limits what mapmakers can do with maps.
If your game freezes/crashes, simply check the log, and when you'll have all kind of mentions of 'triangle errors', it's the pathfinding bug.