It's getting worse but maybe the way it does helps you figure it out. I played the same map E2M3 at the same spot. This time I just saved 2 or 3 times until the game crashes. Now this is interesting, the quicksave from 1890 crashes 1890 but works in 1878. So it is somehow corrupted but you only stopped the uncontrolled growth. https://bytes.one/upload/e2m3_quicksave.zip
It's no big deal for me but this could be one of the more serious bugs which affects at least some people.
Can you confirm the crash with my savegame in 1890 on your computer?