Log below. Win 8.1, 64 bit. It seems to happen approximately when mining stone in the second mission of the first campaign, after putting fuel in the inserter, possibly when the message about rotating the other inserter would pop up. It also happened in the 3rd mission pretty early on.

I'll test 32 ...

Yeah probably most people won't get the reference, unless they either *really* care or happen to watch The Daily Show.

Factorio ~ Factorial
Factorial = function producing product series
Multiple Factorios = product series
China put a recent ban on wordplay.

All the pieces are there.

When the sequel comes out, Factorio will be my favorite product series.