Null reference exception regarding a raycast?

Unity Engine
1

Hey all. In my multiplayer game of Hunter vs Hunted the hunted team have to complete objectives. I set up the following script for this…

	void Update () {
		
		if (Input.GetButtonDown("Fire2")){
			
			NetworkViewID viewID = Network.AllocateViewID();
			
			networkView.RPC("RaycastObjective",RPCMode.AllBuffered, viewID);
			
			
			
		}
						
	}


	[RPC]
	void RaycastObjective(NetworkViewID viewID){
		
		RaycastHit ObjectiveHit = new RaycastHit();
		Ray objRay = Camera.main.ScreenPointToRay(Input.mousePosition);
	
		if (Physics.Raycast(objRay, out ObjectiveHit, 400))
		{
				
				if (ObjectiveHit.transform.name == "IDCard")
			{
				
			currentobjective = 1;
			Debug.Log("Hit Keycard!");	
			Destroy(IDCard);
				
			}
			
				if (ObjectiveHit.transform.name == "Generator")
			{
				
				
				if (currentobjective == 1)
				{
					
				Debug.Log("Generator Activated!");
				currentobjective = 2;
					
					
				}
				
				
			}
				
				
		}

The problem is that when the Hunter team spawns they get this error…

"NullReferenceException
UnityEngine.Camera.ScreenPointToRay (Vector3 position) (at C:/BuildAgent/work/ea95e74f6e5f192d/Runtime/ExportGenerated/Editor/UnityEngineCamera.cs:379)
Obj_Sketchup.RaycastObjective (NetworkViewID viewID) (at Assets/Scripts/MapScripts/Obj_Sketchup.cs:50)
UnityEngine.NetworkView:RPC(String, RPCMode, Object[ ])
Obj_Sketchup:Update() (at Assets/Scripts/MapScripts/Obj_Sketchup.cs:32)"

From what this error says it means that the lines responsible for the error are…

networkView.RPC("RaycastObjective",RPCMode.AllBuffered, viewID);

and

Ray objRay = Camera.main.ScreenPointToRay(Input.mousePosition);

I can’t for the life of me work out why I would be getting a null reference exception error? I have all cameras tagged properly and it seems odd that only one team are getting the error. What would you suggest for a work around?

2

Bump (If I may)