Had a forgotten beast attack some time ago, whose breath caused blistering and bleeding. This proved entirely nonlethal, but the blisters never went away, leaving me with perpetually bleeding, but otherwise happy dorfs. Aside from the red paint job of just about every surface, this really didn't cause any problems. Eventually, I saved and quit.

As soon as I loaded the game up the next time I played, there was a sudden wave of suffocations all at once, shortly after the game was unpaused post-loading, killing about 10 dorfs. This was perplexing, but I didn't think too much of it. Played for awhile, saved, and quit.

NEXT time I loaded up the game, the same thing happened: a wave of mass suffocations. I force quit this time and took inventory of who it was who was suffocating and where they were at this time, and they were all highly blistered dorfs. However, not all of the blistered ones died, and there seemed to be no rhyme or reason as to which ones died and which ones did not, but it -was- consistent every time I loaded. Played for awhile longer, saved, and quit.

Loaded it up again, and wouldn't you know it, the same thing happened, this time 20 dorfs keeled over shortly after unpausing from the load. So I force quit, and am now uploading the save for the purpose of bug stomping.

The bug isn't so much that the forgotten beast's breath eventually kills the dorfs--that's all part of the fun! The problem is that it always (and only) does so immediately following loading the game.

Some random creatures have been modded in, but the game is otherwise standard.