NullReferenceException: Object reference not set to an instance of an object
A NullReferenceException indicates that a variable that is supposed to be set is unset. Its most commonly a sign that something should be set on the Inspector properties of a particular GameObject, but isn’t.
In this part, it is likely that something on the PlayerController component is not set in your Scene. You can have a look at line 49 of your PlayerController script to see which property that is.