Piston Crash Bug (Reproducible)

Included is a world file. There should be a piston portcullis immediately in front of the user once they spawn.

What I expect to happen: I flick the lever and the bottom piston row successfully double extends, then retracts.

What happens: If I flick the lever (might need to do so twice), the pistons in the bottom double extender row suddenly pause, then fire randomly (which they normally should not), then the game crashes, all in that order.