RPC call: parameter suddenly null

Questions & Answers
1

Hi guys i have this werid bug where a int parameter passed to an RPC suddenly becomes null. The error message looks like this:

Sending RPC failed because 'UpdateCallbackVariablesUnit' parameter 7 was null
UnityEngine.NetworkView:RPC(String, NetworkPlayer, Object[])
MouseFeedbackControl:UpdateTopSelectedUnit(NetworkPlayer, Int32) (at Assets/Scripts/MouseFeedbackControl.cs:307)

The RPC is called by this line in OnGUI() in the client:

networkView.RPC ("UpdateTopSelectedUnit", RPCMode.Server, Network.player, 0);

And here is the code containing the error. The function is supposed to sync the client to the server (authoritative server):

[RPC] public void UpdateTopSelectedUnit(NetworkPlayer player, int index) 
	{
	
		int spellcasttype = 0;
		int spellID = 0;
		int buildID = 0;
		string spellname = null;
		string buildname = null;
		
		// PLAYER 1
		if(player.ToString() == "1")
		{
			
			if(selectedUnits1.Count > 0)
			{
				topSelectedUnit1 = selectedUnits1[0] as GameObject;
				
				if(topSelectedUnit1.GetComponent<Unit>().UnitSpells.Count > 0)
					{
					spellID = (int)topSelectedUnit1.GetComponent<Unit>().UnitSpells[index];
					spellname = topSelectedUnit1.GetComponent<Unit>().UnitSpellNames[index] as string;
					spellcasttype = (int)topSelectedUnit1.GetComponent<Unit>().UnitSpellCastType[index];
					}
					
				if(topSelectedUnit1.GetComponent<Unit>().UnitKnowArray.Count > 0)
					{
					buildID = (int)topSelectedUnit1.GetComponent<Unit>().UnitKnowArray[index];
					buildname = topSelectedUnit1.GetComponent<Unit>().UnitKnowNamesArray[index] as string;
					}
//error is in the following line
				networkView.RPC("UpdateCallbackVariablesUnit", player, player, 
				                     topSelectedUnit1 != null, 
				                     !topSelectedUnit1.GetComponent<Unit>().isStationary,
				                     topSelectedUnit1.GetComponent<Unit>().unitHasAttack,
				                     topSelectedUnit1.GetComponent<Unit>().isBarracks,
				                	 spellcasttype,
				                	 spellID,
				               		 spellname,
				              		 buildID,
				              		 buildname,
				     				 topSelectedUnit1.GetComponent<Unit>().UnitSpells.Count,
				               		 topSelectedUnit1.GetComponent<Unit>().UnitKnowArray.Count);
			}
			else 
				topSelectedUnit1 =  null;
		}
}

I can’t see where the mistake is, please help.

2

Solved: since spellname and buildname aren’t always changed from their initial value null, they were sometimes sent with the RPC as null, causing the error.