Using the preview version of 2.0 on .21, when I open the click the button to open the UI panel for the fuel balancer, it opens, but is empty and non-interactable (can't drag it around, clicks drop through it to stuff under, etc). Looking in the output log, I am seeing: NullReferenceException: Object reference not set to an instance of an object at Tac.FuelBalanceController.IsControllable () [0x00000] in <filename unknown>:0 at Tac.MainWindow.DrawWindowContents (Int32 windowID) [0x00000] in <filename unknown>:0 at Tac.Window`1[T].PreDrawWindowContents (Int32 windowId) [0x00000] in <filename unknown>:0 at UnityEngine.GUILayout+LayoutedWindow.DoWindow (Int32 windowID) [0x00000] in <filename unknown>:0 at UnityEngine.GUI.CallWindowDelegate (UnityEngine.WindowFunction func, Int32 id, UnityEngine.GUISkin _skin, Int32 forceRect, Single width, Single height, UnityEngine.GUIStyle style) [0x00000] in <filename unknown>:0 (Filename: Line: -1) GUI Error: You are pushing more GUIClips than you are popping. Make sure they are balanced) (Filename: Line: 396) ArgumentException: Getting control 0's position in a group with only 0 controls when doing Repaint Aborting at UnityEngine.GUILayoutGroup.GetNext () [0x00000] in <filename unknown>:0 at UnityEngine.GUILayoutUtility.BeginLayoutGroup (UnityEngine.GUIStyle style, UnityEngine.GUILayoutOption[] options, System.Type LayoutType) [0x00000] in <filename unknown>:0 at UnityEngine.GUILayout.BeginScrollView (Vector2 scrollPosition, Boolean alwaysShowHorizontal, Boolean alwaysShowVertical, UnityEngine.GUIStyle horizontalScrollbar, UnityEngine.GUIStyle verticalScrollbar, UnityEngine.GUIStyle background, UnityEngine.GUILayoutOption[] options) [0x00000] in <filename unknown>:0 at UnityEngine.GUILayout.BeginScrollView (Vector2 scrollPosition, UnityEngine.GUILayoutOption[] options) [0x00000] in <filename unknown>:0 at Tac.MainWindow.DrawWindowContents (Int32 windowID) [0x00000] in <filename unknown>:0 at Tac.Window`1[T].PreDrawWindowContents (Int32 windowId) [0x00000] in <filename unknown>:0 at UnityEngine.GUILayout+LayoutedWindow.DoWindow (Int32 windowID) [0x00000] in <filename unknown>:0 at UnityEngine.GUI.CallWindowDelegate (UnityEngine.WindowFunction func, Int32 id, UnityEngine.GUISkin _skin, Int32 forceRect, Single width, Single height, UnityEngine.GUIStyle style) [0x00000] in <filename unknown>:0 Hope this helps (also hope I am not the only one running into this / doing something dumb).