From 1.7 tracker: pWn3d1337/Techguns#217

As title says - anyone attempting to view a Howling Moon werewolf using a TechGun gun (even the wolf themselves in 3rd person) gets a hard crash. Replicated with and without FoamFix and BetterFPS.

Log here: https://pastebin.com/vBz81ubS

Yep, classic cross mod problem. When I get the model of a player it's safe to assume it's a ModelPlayer? Right? ... Then some mod comes along and replaces the player model.

I added an Instanceof check for next version that should fix this.