Creating Missing Item

I'm not sure how Skill Tree would be connected, but when my players are picking up Hemp seeds, pumpkins etc

I get the error code: "Creating item with an amount less than 1 (whatever item)"

And when they try to eat food, it doesn't increase their hunger. 

Now, I know it's skilltree, because when I unload the plugin everything works fine. 

I did customize the config recently, but I wouldn't know what I could have possibly have done to cause this error. 

SkillTree.json

I think I fixed it.