Extreme slowdowns

[Loobinex]

Load this zip in 1.0.0.3940, it is assmist level 6: fx1g0000.zip

[Loobinex]

After a bit of investigation, it is the training vampires that are a problem. You can remove all vampires from the training room and slowdowns stop.

Then you can continue to pick up vampires from the now empty training room:

Notice the vampire on the left, is now has the in-hand animation. Vampires are somehow duplicated.

[Loobinex]

#3234 stopped the slowdowns by breaking the mapwho chain. The original error of duplicate vampires hidden in the training room remains.
The only path to reproduction so far is to play the map for many hours until it happens, or not and then retry it.