Behavior packs render game unplayable in some cases and instant crashes it

Build: 418100
Summary:
Loading a map that uses a behavior pack, almost always crashes the world.
Impact:
Critical game feature that renders much of the marketplace content that uses behavior packs unplayable. I have attached an example behavior pack that I use for Infinity Dungeon which I can't get to load at all.
Repro Steps:
1.Visit https://minecraft.net/en-us/addons/ and download alien invasion
2.install it and try to play it
Observed Results: Crashed
Expected Results: not crashed and working
Screenshots/Videos attached: no