Can anyone help me get my projectile to work c#

Questions & Answers
1

Basically i had this working in Javascript, but im converting all my scripts to c#.

This is currently my main script so it’s important it works correctly, i think i’ve made too many changes
and i’m getting very lost.
When i currently play and press my mouse button its giving me a null reference error.

Any help would be highly appreciated.

using UnityEngine;
using System.Collections;

public class ThrowKnife : MonoBehaviour 
{
	public GameObject knife;
	public int power; 
	public bool heldDown= false;
	
	
	void  Start ()
	{
		knife = Resources.Load ("Knife_Prefab") as GameObject;
	}
	
	void  Update ()
	{   
		power = 20;
		
		if(Input.GetMouseButtonDown(0))
		{
			
			
			RaycastHit vHit = new RaycastHit();
			Ray vRay = Camera.main.ScreenPointToRay(Input.mousePosition);
			if(Physics.Raycast(vRay, out vHit, 10000)) 
			{
				Rigidbody clone;
				clone = Instantiate(knife, transform.position+Camera.main.transform.forward * -2, Quaternion.identity)as Rigidbody; 
				clone.transform.LookAt(vHit.point); 
				clone.velocity = transform.TransformDirection(Vector3.forward * power);
				power = 20;

			}
		}
	}
}
2

I had issue before when trying to cast to Rogidbody with Instantiate.

if(Physics.Raycast(vRay, out vHit, 10000)) 
{
       GameObject clone = (GameObject)Instantiate(knife, transform.position+Camera.main.transform.forward * -2, Quaternion.identity; 
      clone.transform.LookAt(vHit.point); 
      clone.GetComponent<Rigidbody>().velocity = transform.TransformDirection(Vector3.forward * power);
      power = 20;
}