Question Need help with "NullReferenceException: Object reference not set to an instance of an object" error

I'm working on a ML Agents project where the AI learns through behaviour cloning exclusively to park a car. I recently revised the entire Agent script for general optimisation and whatnot, and after doing so I get this error.


I also can't add the "CarController" script to the "Car Controller" field in the Agent script.



As you see the names of the scripts match with file name and everything. I have no clue why I have this issue and I've tried finding people with the same issue as me but nothing seems to work.

 

where do you define what rb is in the CarController script?
you can see it is underlined in your IDE which probably means you haven't defined it, you likely forgot to reference it in Start like you did for the CarParkingAgent script

 

is private "Rigidbody rb;" not enough? Do I need to reference GetComponent<Rigidbody>(); in both scripts? Ill try that thankyou for your reply