Animation Rigging IK invalidOperationException: TransformStreamHandle cannot be resolved.

I am working on making a 3d character hold items instead of the telekinetic floating tools characters currently have in my game. I was following this tutorial and I made it to checking the results at 2:45 but mine doesn't work. It throws the exception thrown in this screenshot.



For this screenshot I cut out all of my character scripts to make sure the issue isn't coming from them. From what I have found online, this exception has to do with the hierarchy of the character. So I made another version where the xbot gameobject was the root of the character and it worked, but that is incompatible with all my other scripts as I put collision and logic on the "Player" gameobject. The tutorial has the same hierarchy setup for the character as I do. Can anyone tell me what is going on here? Do I actually need to make xbot the root of the entire character?

 

Having similar issue, did you resolve this?