- Open Standalone profiler
- See that the profiler window stays black (nothing is rendered.)
- See error messages in the console.

IndexOutOfRangeException: Index was outside the bounds of the array.
UnityEditor.ProfilerWindow.OnGUI () (at D:/work/unity-2019.3/Modules/ProfilerEditor/ProfilerWindow/ProfilerWindow.cs:1269)
System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <437ba245d8404784b9fbab9b439ac908>:0)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <437ba245d8404784b9fbab9b439ac908>:0)
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) (at <437ba245d8404784b9fbab9b439ac908>:0)
UnityEditor.HostView.Invoke (System.String methodName, System.Object obj) (at D:/work/unity-2019.3/Editor/Mono/HostView.cs:381)
UnityEditor.HostView.Invoke (System.String methodName) (at D:/work/unity-2019.3/Editor/Mono/HostView.cs:375)
UnityEditor.HostView.InvokeOnGUI (UnityEngine.Rect onGUIPosition, UnityEngine.Rect viewRect) (at D:/work/unity-2019.3/Editor/Mono/HostView.cs:351)
UnityEditor.DockArea.DrawView (UnityEngine.Rect viewRect, UnityEngine.Rect dockAreaRect) (at D:/work/unity-2019.3/Editor/Mono/GUI/DockArea.cs:401)
UnityEditor.DockArea.OldOnGUI () (at D:/work/unity-2019.3/Editor/Mono/GUI/DockArea.cs:390)
UnityEngine.UIElements.IMGUIContainer.DoOnGUI (UnityEngine.Event evt, UnityEngine.Matrix4x4 parentTransform, UnityEngine.Rect clippingRect, System.Boolean isComputingLayout, UnityEngine.Rect layoutSize, System.Action onGUIHandler, System.Boolean canAffectFocus) (at D:/work/unity-2019.3/Modules/UIElements/IMGUIContainer.cs:276)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr) (at D:/work/unity-2019.3/Modules/IMGUI/GUIUtility.cs:187)

Note: this bug is not easy to reproduce. you need to have a layout already saved with the splitter values. And then use a new version of Unity that will try to access this layout and fails because the type of splitterState has failed. In order to reproduce you might need to clear out all layouts in between testing on different versions.

Note: When the layout is saved and not properly reloaded this would affect all versions supporting the standalone profiler: 19.3, 20.1 and 20.2