unity2018,安装2.8.0和2.11.0的插件，都会在创建场景后预览报错：

MissingReferenceException: The object of type 'SkinnedMeshRenderer' has been destroyed but you are still trying to access it.
Your script should either check if it is null or you should not destroy the object.

n.a (UnityEngine.SkinnedMeshRenderer A_0, System.String A_1, System.Boolean A_2) (at <f23f19a62c944610ba98639869d48a79>:0)
n.b () (at <f23f19a62c944610ba98639869d48a79>:0)
n.b (System.String A_0) (at <f23f19a62c944610ba98639869d48a79>:0)
LayaAir3D.exportResource (System.Boolean isDebug, System.Int32 Platformindex, System.String lastname) (at <f23f19a62c944610ba98639869d48a79>:0)
LayaAir3D.OnGUI () (at <f23f19a62c944610ba98639869d48a79>:0)
System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <df7127ba07dc446d9f5831a0ec7b1d63>: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 <df7127ba07dc446d9f5831a0ec7b1d63>:0)
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) (at <df7127ba07dc446d9f5831a0ec7b1d63>:0)
UnityEditor.HostView.Invoke (System.String methodName, System.Object obj) (at D:/unity/Editor/Mono/HostView.cs:342)
UnityEditor.HostView.Invoke (System.String methodName) (at D:/unity/Editor/Mono/HostView.cs:336)
UnityEditor.HostView.InvokeOnGUI (UnityEngine.Rect onGUIPosition, UnityEngine.Rect viewRect) (at D:/unity/Editor/Mono/HostView.cs:310)
UnityEditor.DockArea.DrawView (UnityEngine.Rect viewRect, UnityEngine.Rect dockAreaRect, System.Boolean customBorder, System.Boolean floatingWindow, System.Boolean isBottomTab) (at D:/unity/Editor/Mono/GUI/DockArea.cs:361)
UnityEditor.DockArea.OldOnGUI () (at D:/unity/Editor/Mono/GUI/DockArea.cs:320)
UnityEngine.Experimental.UIElements.IMGUIContainer.DoOnGUI (UnityEngine.Event evt, UnityEngine.Matrix4x4 worldTransform, UnityEngine.Rect clippingRect, System.Boolean isComputingLayout) (at D:/unity/Modules/UIElements/IMGUIContainer.cs:266)
UnityEngine.Experimental.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, UnityEngine.Matrix4x4 worldTransform, UnityEngine.Rect clippingRect) (at D:/unity/Modules/UIElements/IMGUIContainer.cs:438)
UnityEngine.Experimental.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e) (at D:/unity/Modules/UIElements/IMGUIContainer.cs:421)
UnityEngine.Experimental.UIElements.IMGUIContainer.HandleEvent (UnityEngine.Experimental.UIElements.EventBase evt) (at D:/unity/Modules/UIElements/IMGUIContainer.cs:401)
UnityEngine.Experimental.UIElements.EventDispatcher.ProcessEvent (UnityEngine.Experimental.UIElements.EventBase evt, UnityEngine.Experimental.UIElements.IPanel panel) (at D:/unity/Modules/UIElements/EventDispatcher.cs:511)
UnityEngine.Experimental.UIElements.EventDispatcher.Dispatch (UnityEngine.Experimental.UIElements.EventBase evt, UnityEngine.Experimental.UIElements.IPanel panel, UnityEngine.Experimental.UIElements.DispatchMode dispatchMode) (at D:/unity/Modules/UIElements/EventDispatcher.cs:307)
UnityEngine.Experimental.UIElements.BaseVisualElementPanel.SendEvent (UnityEngine.Experimental.UIElements.EventBase e, UnityEngine.Experimental.UIElements.DispatchMode dispatchMode) (at D:/unity/Modules/UIElements/Panel.cs:176)
UnityEngine.Experimental.UIElements.UIElementsUtility.DoDispatch (UnityEngine.Experimental.UIElements.BaseVisualElementPanel panel) (at D:/unity/Modules/UIElements/UIElementsUtility.cs:245)
UnityEngine.Experimental.UIElements.UIElementsUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr) (at D:/unity/Modules/UIElements/UIElementsUtility.cs:68)
UnityEngine.GUIUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr) (at D:/unity/Modules/IMGUI/GUIUtility.cs:179)