Living Entity Failling

So, i made a linking entity through block bench. I gave it its model, it's texture, and i gave it everything a normal mob has. 

But, when I clicked save and exit, my mod said it had an error. 

So i checked, EVERYTHING, and i found no answers. So i checked the console and it said a bunch of errors i didnt understand.

So please, do you know an answer? Also im in 2021.1 so you probably already fixed it.