Upon doing some digging I found another issue. It seems that the Editor Preview for the NetworkTransform (?) is glitching out with a NullReferenceException, even if you're not in play mode? Code (csharp): NullReferenceException: Object reference not set to an instance of an object UnityEditor.Networking.NetworkTransformPreview.OnPreviewGUI (Rect r, UnityEngine.GUIStyle background) UnityEditor.ObjectPreview.OnInteractivePreviewGUI (Rect r, UnityEngine.GUIStyle background) (at C:/buildslave/unity/build/Editor/Mono/Inspector/Editor.cs:113) UnityEditor.ObjectPreview.DrawPreview (IPreviewable defaultPreview, Rect previewArea, UnityEngine.Object targets) (at C:/buildslave/unity/build/Editor/Mono/Inspector/Editor.cs:223) UnityEditor.ObjectPreview.DrawPreview (Rect previewArea) (at C:/buildslave/unity/build/Editor/Mono/Inspector/Editor.cs:127) UnityEditor.InspectorWindow.DrawPreviewAndLabels () (at C:/buildslave/unity/build/Editor/Mono/Inspector/InspectorWindow.cs:767) UnityEditor.InspectorWindow.OnGUI () (at C:/buildslave/unity/build/Editor/Mono/Inspector/InspectorWindow.cs:397) System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222) Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation. System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:232) System.Reflection.MethodBase.Invoke (System.Object obj, System.Object parameters) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MethodBase.cs:115) UnityEditor.HostView.Invoke (System.String methodName, System.Object obj) (at C:/buildslave/unity/build/Editor/Mono/HostView.cs:295) UnityEditor.HostView.Invoke (System.String methodName) (at C:/buildslave/unity/build/Editor/Mono/HostView.cs:288) UnityEditor.HostView.InvokeOnGUI (Rect onGUIPosition) (at C:/buildslave/unity/build/Editor/Mono/HostView.cs:255) Here's what I see when I set up a cube GameObject with NetworkTransform: Here's what I see when I set up a character with Opsive's TPC Network Setup script which adds a NetworkTransform automatically: As you can see, they aren't consistent for whatever reason. Do you know what could be triggering this? EDIT: Well it seems that I fixed whatever was causing the unknown message ID call. Must have been something in an override of mine because I double and triple checked the code and it was supposed to be working as nature intended... but whatever. It's not a fault of HLAPI Community Edition. Strike that one off the list... for now.