UnityCollaborate parameter assetGuid is null error

On Unity5.5.0x1-CollabPreview Personal on new Scene i add a Controller GameObject and a button (canvas eventsystem etc). Now when i try to assign a script on the button’s OnClick() through inspector the pop up menu will not show any GameObjects in the Scene sub menu and will throw the following error ,on other hand the Asset sub menu will show the assets properly. Any insight on the subject would be appreciated. Here is the error:


ArgumentNullException: Argument cannot be null.
Parameter name: assetGuid
UnityEditor.Collaboration.CollabData.TryGetLocksOnAssetGUID (System.String assetGuid, System.Collections.Generic.List`1& softLocks) (at C:/buildslave/unity/build/Editor/Mono/Collab/CollabEditorHooks.cs:277)
UnityEditor.Collaboration.CollabData.TryGetSoftlockCount (System.String assetGuid, System.Int32& count) (at C:/buildslave/unity/build/Editor/Mono/Collab/CollabEditorHooks.cs:244)
UnityEditor.Collaboration.SoftLockUIData.GetIconForGUID (SectionEnum section, System.String GUID) (at C:/buildslave/unity/build/Editor/Mono/Collab/CollabEditorHooks.cs:417)
UnityEditor.Collaboration.CollabProjectHook.OnProjectWindowItemIconOverlay (System.String guid, Rect drawRect) (at C:/buildslave/unity/build/Editor/Mono/Collab/CollabEditorHooks.cs:23)
UnityEditor.ObjectListArea+LocalGroup.DrawIconAndLabel (Rect rect, UnityEditor.FilterResult filterItem, System.String label, UnityEngine.Texture2D icon, Boolean selected, Boolean focus) (at C:/buildslave/unity/build/Editor/Mono/ObjectListLocalGroup.cs:1333)
UnityEditor.ObjectListArea+LocalGroup.DrawItem (Rect position, UnityEditor.FilterResult filterItem, UnityEditor.BuiltinResource builtinResource, Boolean isFolderBrowsing) (at C:/buildslave/unity/build/Editor/Mono/ObjectListLocalGroup.cs:714)
UnityEditor.ObjectListArea+LocalGroup.DrawInternal (Int32 beginIndex, Int32 endIndex, Single yOffset) (at C:/buildslave/unity/build/Editor/Mono/ObjectListLocalGroup.cs:192)
UnityEditor.ObjectListArea+Group.Draw (Single yOffset, Vector2 scrollPos) (at C:/buildslave/unity/build/Editor/Mono/ObjectListGroup.cs:144)
UnityEditor.ObjectListArea.HandleListArea () (at C:/buildslave/unity/build/Editor/Mono/ObjectListArea.cs:1367)
UnityEditor.ObjectListArea.OnGUI (Rect position, Int32 keyboardControlID) (at C:/buildslave/unity/build/Editor/Mono/ObjectListArea.cs:562)
UnityEditor.ObjectSelector.GridListArea () (at C:/buildslave/unity/build/Editor/Mono/ObjectSelector.cs:758)
UnityEditor.ObjectSelector.OnObjectGridGUI () (at C:/buildslave/unity/build/Editor/Mono/ObjectSelector.cs:746)
UnityEditor.ObjectSelector.OnGUI () (at C:/buildslave/unity/build/Editor/Mono/ObjectSelector.cs:707)
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:249)
UnityEditor.HostView.Invoke (System.String methodName) (at C:/buildslave/unity/build/Editor/Mono/HostView.cs:242)
UnityEditor.HostView.OnGUI () (at C:/buildslave/unity/build/Editor/Mono/HostView.cs:76)

Well in case someone else stumble on this i ll answer to myself. Turns out to be a bug on Collaborate preview and will be fixed to 5.6 release according to Unity. Work around this, is to turn off the Collaborate service while working with UIs and turn it back on when finished. link forum