Thanks to forum user @ozraven for this:

  Fixed a null ref which occurred when clicking in a debug window

Author: linuxgurugamer

ChangeLog.txt

@@ -1,5 +1,9 @@
 ChangeLog
 
+3.4.3.6
+	Thanks to forum user @ozraven for this:
+		Fixed a null ref which occurred when clicking in a debug window
+
 3.4.3.5
 	Added AssemblyFileVersion
 	Updated version file for 1.12

EditorExtensionsRedux.version

@@ -6,12 +6,12 @@
     "MAJOR": 3,
     "MINOR": 4,
     "PATCH": 3,
-    "BUILD": 5
+    "BUILD": 6
   },
   "KSP_VERSION": {
     "MAJOR": 1,
     "MINOR": 12,
-    "PATCH": 0
+    "PATCH": 5
   },
   "KSP_VERSION_MIN": {
     "MAJOR": 1,

EditorExtensionsRedux/AssemblyVersion.cs

@@ -10,5 +10,5 @@
 
  using System.Reflection;
 
- [assembly: AssemblyVersion("3.4.3.4")]
- [assembly: AssemblyFileVersion("3.4.3.4")]
+ [assembly: AssemblyVersion("3.4.3.6")]
+ [assembly: AssemblyFileVersion("3.4.3.6")]

EditorExtensionsRedux/EditorExtensionsRedux.cs

@@ -1479,7 +1479,7 @@ public class Config
                                 //var gizmosRotate = HighLogic.FindObjectsOfType<EditorGizmos.GizmoRotate> ();
                                 //								if (gizmoRotateHandle == null)
                                 //									gizmoRotateHandle = HighLogic.FindObjectOfType<EditorGizmos.GizmoRotateHandle> ();
-                                float rotation = FineAdjustWindow.Instance.rotation;
+                                float rotation = FineAdjustWindow.Instance.rotationZZ;
 
                                 if (Input.GetKey(cfg.KeyMap.Down))
                                 {

EditorExtensionsRedux/FineAdjustWindow.cs

@@ -82,7 +82,7 @@ enum AdjustmentType
 		AdjustmentType adjType = AdjustmentType.translation;
 		string adjTypeStr = "Translation";
 		public float offset = 0.01f;
-		public float rotation = 1.0f;
+		public float rotationZZ = 1.0f;
 		public int offsetDeltaIndex = 2;
 		public int rotationdeltaIndex = 0;
 
@@ -205,9 +205,9 @@ void WindowContent (int windowID)
 				if (GUILayout.Button ("-", GUILayout.Width (20))) {
 					switch (adjType) {
 					case AdjustmentType.rotation:
-						rotation -= getDelta (rotationdeltaIndex);
-						if (rotation <= 0.0f)
-							rotation = getDelta (rotationdeltaIndex);
+						rotationZZ -= getDelta (rotationdeltaIndex);
+						if (rotationZZ <= 0.0f)
+							rotationZZ = getDelta (rotationdeltaIndex);
 
 						break;
 					case AdjustmentType.translation:
@@ -220,7 +220,7 @@ void WindowContent (int windowID)
 				}
 				switch (adjType) {
 				case AdjustmentType.rotation:
-					GUILayout.Label (rotation.ToString (), "TextField");
+					GUILayout.Label (rotationZZ.ToString (), "TextField");
 					break;
 				case AdjustmentType.translation:
 					GUILayout.Label (offset.ToString (), "TextField");
@@ -230,7 +230,7 @@ void WindowContent (int windowID)
 				if (GUILayout.Button ("+", GUILayout.Width (20))) {
 					switch (adjType) {
 					case AdjustmentType.rotation:
-						rotation += getDelta (rotationdeltaIndex);
+						rotationZZ += getDelta (rotationdeltaIndex);
 						break;
 					case AdjustmentType.translation:
 						offset += getDelta (offsetDeltaIndex);

EditorExtensionsRedux/StockSettings.cs

@@ -37,7 +37,7 @@ public override bool Enabled(MemberInfo member, GameParameters parameters)
             return true;
         }
 
-        bool unread = false;
+        //bool unread = false;
         public override bool Interactible(MemberInfo member, GameParameters parameters)
         {
 

EditorExtensionsRedux/Utility.cs

@@ -14,7 +14,7 @@ public static Part GetPartUnderCursor()
             EditorLogic ed = EditorLogic.fetch;
             if (ed != null && Physics.Raycast(ray, out hit))
             {
-                return ed.ship.Parts.Find(p => p.gameObject == hit.transform.gameObject);
+                return ed.ship.Parts.Find(p => p != null && p.gameObject == hit.transform.gameObject);
             }
             return null;
         }

GameData/EditorExtensionsRedux/EditorExtensionsRedux.version

@@ -6,7 +6,12 @@
     "MAJOR": 3,
     "MINOR": 4,
     "PATCH": 3,
-    "BUILD": 4
+    "BUILD": 6
+  },
+  "KSP_VERSION": {
+    "MAJOR": 1,
+    "MINOR": 12,
+    "PATCH": 5
   },
   "KSP_VERSION_MIN": {
     "MAJOR": 1,