Why is my rig Ai headless

Hi all
I am making a horror game in which a creepy doll is the antagonist.The doll I had before was not that creepy so I downlaoded a free doll head from the creator marketplace which is this one [https://create.roblox.com/marketplace/asset/3147163924/Creepy-Doll-Head?pageNumber=1&pagePosition=0&keyword=+doll+head]
but after I renamed it to ‘Head’ and put it in the Doll and tested the game the doll was headless but its AI was still functional.

I really don’t know the reason behind this and was wondering if anyone here can help me out pleas

Thank you!

Can I see a screenshot of the explorer of the character?

The doll is headless probably because the Head is falling trough the floor.