Fixed logic for setting GameStarted block in new Flowcharts

Also added safety cleanup code to remove null items in variable list in
cleanup.

Assets/Fungus/Flowchart/Editor/FlowchartMenuItems.cs

@@ -13,6 +13,14 @@ namespace Fungus
 		{
 			GameObject go = SpawnPrefab("Flowchart");
 			go.transform.position = Vector3.zero;
+
+			// Only the first created Flowchart in the scene should have a default GameStarted block
+			if (GameObject.FindObjectsOfType<Flowchart>().Length > 1)
+			{
+				Block block = go.GetComponent<Block>();
+				block.eventHandler = null;
+				GameObject.DestroyImmediate(block.eventHandler);
+			}
 		}
 
 		[MenuItem("Tools/Fungus/Create/Fungus Logo", false, 1000)]

Assets/Fungus/Flowchart/Scripts/Flowchart.cs

@@ -247,6 +247,10 @@ namespace Fungus
 
 			Block[] blocks = GetComponentsInChildren<Block>();
 
+			// Remove any null entries in the variables list
+			// It shouldn't happen but it seemed to occur for a user on the forum 
+			variables.RemoveAll(item => item == null);
+
 			foreach (Variable variable in GetComponents<Variable>())
 			{
 				if (!variables.Contains(variable))
@@ -310,14 +314,7 @@ namespace Fungus
         }
 
 	    protected virtual void Initialize()
-	    {
-            // If there are other flowcharts in the scene and the selected block has the default name, then this is probably a new block.
-            // Reset the event handler of the new flowchart's default block to avoid crashes.
-            if (selectedBlock && cachedFlowcharts.Count > 1 && selectedBlock.blockName == DEFAULT_BLOCK_NAME)
-            {
-                selectedBlock.eventHandler = null;
-            }
-        }
+	    {}
 
 		protected virtual Block CreateBlockComponent(GameObject parent)
 		{