diff --git a/Scripts/Editor/NodeEditorAction.cs b/Scripts/Editor/NodeEditorAction.cs
index 804b4c6..f4fcdb7 100644
--- a/Scripts/Editor/NodeEditorAction.cs
+++ b/Scripts/Editor/NodeEditorAction.cs
@@ -127,7 +127,7 @@ public partial class NodeEditorWindow {
             if (!_portConnectionPoints.ContainsKey(draggedOutput)) return;
             Vector2 from = _portConnectionPoints[draggedOutput].center;
             Vector2 to = draggedOutputTarget != null ? portConnectionPoints[draggedOutputTarget].center : WindowToGridPosition(Event.current.mousePosition);
-            Color col = NodeEditorPreferences.GetTypeColor(draggedOutput.type);
+            Color col = NodeEditorPreferences.GetTypeColor(draggedOutput.ValueType);
             col.a = 0.6f;
             DrawConnection(from, to, col);
         }
diff --git a/Scripts/Editor/NodeEditorGUI.cs b/Scripts/Editor/NodeEditorGUI.cs
index 578eb3e..0ba190d 100644
--- a/Scripts/Editor/NodeEditorGUI.cs
+++ b/Scripts/Editor/NodeEditorGUI.cs
@@ -129,7 +129,7 @@ public partial class NodeEditorWindow {
                     if (!input.IsConnectedTo(output)) input.Connect(output);
                     if (!_portConnectionPoints.ContainsKey(input)) continue;
                     Vector2 to = _portConnectionPoints[input].center;
-                    DrawConnection(from, to, NodeEditorPreferences.GetTypeColor(output.type));
+                    DrawConnection(from, to, NodeEditorPreferences.GetTypeColor(output.ValueType));
                 }
             }
         }
@@ -235,7 +235,7 @@ public partial class NodeEditorWindow {
 
     private void DrawTooltip() {
         if (hoveredPort != null) {
-            Type type = hoveredPort.type;
+            Type type = hoveredPort.ValueType;
             GUIContent content = new GUIContent();
             content.text = TypeToString(type);
             Vector2 size = NodeEditorResources.styles.tooltip.CalcSize(content);
@@ -246,6 +246,7 @@ public partial class NodeEditorWindow {
     }
 
     private string TypeToString(Type type) {
+        if (type == null) return "null";
         if (type == typeof(float)) return "float";
         else if (type == typeof(int)) return "int";
         else if (type == typeof(long)) return "long";
@@ -276,6 +277,6 @@ public partial class NodeEditorWindow {
                 int i = s.IndexOf('[');
                 return s.Substring(0,i) + "["+rank+"]" + s.Substring(i);
             }
-        } else return hoveredPort.type.ToString();
+        } else return hoveredPort.ValueType.ToString();
     }
 }
\ No newline at end of file
diff --git a/Scripts/Editor/NodeEditorGUILayout.cs b/Scripts/Editor/NodeEditorGUILayout.cs
index 8ec6fbf..efbd51d 100644
--- a/Scripts/Editor/NodeEditorGUILayout.cs
+++ b/Scripts/Editor/NodeEditorGUILayout.cs
@@ -7,7 +7,7 @@ using UnityEditor;
 using UnityEngine;
 
 /// <summary> UNEC-specific version of <see cref="EditorGUILayout"/> </summary>
-public static class NodeEditorGUILayout  {
+public static class NodeEditorGUILayout {
 
     public static void PropertyField(SerializedProperty property, bool includeChildren = true) {
         if (property == null) throw new NullReferenceException();
@@ -29,7 +29,7 @@ public static class NodeEditorGUILayout  {
                 else EditorGUILayout.PropertyField(property, includeChildren);
                 rect = GUILayoutUtility.GetLastRect();
                 rect.position = rect.position - new Vector2(16, 0);
-            // If property is an output, display a text label and put a port handle on the right side
+                // If property is an output, display a text label and put a port handle on the right side
             } else if (port.direction == NodePort.IO.Output) {
                 EditorGUILayout.LabelField(property.displayName, NodeEditorResources.styles.outputPort);
                 rect = GUILayoutUtility.GetLastRect();
@@ -38,7 +38,7 @@ public static class NodeEditorGUILayout  {
 
             rect.size = new Vector2(16, 16);
 
-            DrawPortHandle(rect, port.type);
+            DrawPortHandle(rect, port.ValueType);
 
             // Register the handle position
             Vector2 portPos = rect.center;
diff --git a/Scripts/Node.cs b/Scripts/Node.cs
index ca21f0f..6df05cd 100644
--- a/Scripts/Node.cs
+++ b/Scripts/Node.cs
@@ -74,6 +74,7 @@ public abstract class Node : ScriptableObject {
     public bool RemoveInstancePort(string fieldName) {
         NodePort port = GetPort(fieldName);
         if (port == null || port.IsStatic) return false;
+        port.ClearConnections();
         ports.Remove(fieldName);
         return true;
     }
diff --git a/Scripts/NodeDataCache.cs b/Scripts/NodeDataCache.cs
index b542be1..30d98ab 100644
--- a/Scripts/NodeDataCache.cs
+++ b/Scripts/NodeDataCache.cs
@@ -23,14 +23,12 @@ public static class NodeDataCache {
         }
 
         // Cleanup port dict - Remove nonexisting static ports - update static port types
-        foreach (NodePort port in ports.Values) {
+        foreach (NodePort port in ports.Values.ToList()) {
             if (staticPorts.ContainsKey(port.fieldName)) {
                 NodePort staticPort = staticPorts[port.fieldName];
                 if (port.IsDynamic || port.direction != staticPort.direction) ports.Remove(port.fieldName);
-                else port.type = staticPort.type;
-            } else {
-                ports.Remove(port.fieldName);
-            }
+                else port.ValueType = staticPort.ValueType;
+            } else if (port.IsStatic) ports.Remove(port.fieldName);
         }
         // Add missing ports
         foreach (NodePort staticPort in staticPorts.Values) {
diff --git a/Scripts/NodePort.cs b/Scripts/NodePort.cs
index 8fcb958..6a85b78 100644
--- a/Scripts/NodePort.cs
+++ b/Scripts/NodePort.cs
@@ -103,6 +103,11 @@ public class NodePort {
         object[] objs = new object[ConnectionCount];
         for (int i = 0; i < ConnectionCount; i++) {
             NodePort connectedPort = connections[i].Port;
+            if (connectedPort == null) { // if we happen to find a null port, remove it and look again
+                connections.RemoveAt(i);
+                i--;
+                continue;
+            }
             objs[i] = connectedPort.GetOutputValue();
         }
         return objs;