[1.12.2] Spawning an entity resulting in a crash

[abused_master]

Hello everyone, so earlier today i was attempting to create an entity, now this was the first time i've ever messed with entities so i half didn't know what i was doing, but the issue i'm running into is that, when i attempt to spawn the entity, instantly the game crashes.

This is the crash im getting:

https://pastebin.com/gmDzeLhA

 

Here's my entity code: https://pastebin.com/mjFRA57E

And im attempting to spawn the entity via an item using world.spawnEntity();

 

    @Override
    public ActionResult<ItemStack> onItemRightClick(World world, EntityPlayer player, EnumHand hand) {
        world.spawnEntity(new EntityKnowledge(world, player));
        return super.onItemRightClick(world, player, hand);
    }

Does anyone happen to know why exactly this might be happening?

[FredTargaryen]

The log says the crash is because of line 26 of EntityKnowledge, in the constructor, but in your pasted EntityKnowledge code line 26 is just defining canBeRidden... is that definitely the same EntityKnowledge code that produced that crash log?

[V0idWa1k3r]

You are overriding Entity#entityInit to do nothing. entityInit is responsible for registering keys into the data manager of the entity. In your implementation no keys are being registered so when the game tries to set the health for the mob it crashes because health is managed via datamanager.