Please see Using code tags properly to format your code on the forums.
Please also include the full error message in the future, as you have left out important details like which line number the error is on.
Based on a cursory glance of your code I see a problem with these lines:
isWalkingHash = Animator.StringToHash("isWalking");
isRunningHash = Animator.StringToHash("isRunning");
You need to use a lowercase “a” for “animator” here because you have declared your “animator” variable with a lowercase a here:
Animator animator;