NullReferenceException when clicking at "Combine"

[inkuxuan]

Hi.
Thank you for making this tool.
I encountered a problem and think that I should report it here.
This problem occurs when I'm trying to combine meshes of the original Hakka (unmodified)'s meshes on Android platform.
After importing Mesh Combiner, select target avatar and hit "+",
multiple mesh renderers are added automatically.
Next, hit "Auto create" in "destination", a new mesh renderer is created automatically.
Finally when I hit "Combine" button, this exception came up:

NullReferenceException: Object reference not set to an instance of an object
JLChnToZ.EditorExtensions.SkinnedMeshCombiner.VertexCutter+BlendShapeCutter.Apply (UnityEngine.Mesh mesh) (at Assets/JLChnToZ/Common/Editor/SkinnedMeshCombiner/VertexCutter.cs:352)
JLChnToZ.EditorExtensions.SkinnedMeshCombiner.VertexCutter.Apply (UnityEngine.Mesh mesh) (at Assets/JLChnToZ/Common/Editor/SkinnedMeshCombiner/VertexCutter.cs:107)
JLChnToZ.EditorExtensions.SkinnedMeshCombiner.SkinnedMeshCombinerCore.Add (UnityEngine.SkinnedMeshRenderer source, JLChnToZ.EditorExtensions.SkinnedMeshCombiner.CombineBlendshapeFlags[] bakeFlags, JLChnToZ.EditorExtensions.SkinnedMeshCombiner.CombineMeshFlags mergeFlags) (at Assets/JLChnToZ/Common/Editor/SkinnedMeshCombiner/SkinnedMeshCombinerCore.cs:166)
JLChnToZ.EditorExtensions.SkinnedMeshCombiner.SkinnedMeshCombinerCore.Combine (System.Collections.Generic.ICollection`1[T] sources, UnityEngine.SkinnedMeshRenderer destination, JLChnToZ.EditorExtensions.SkinnedMeshCombiner.CombineMeshFlags mergeFlags, JLChnToZ.EditorExtensions.SkinnedMeshCombiner.BlendShapeCopyMode blendShapeCopyMode, System.Collections.Generic.IDictionary`2[TKey,TValue] boneRemap) (at Assets/JLChnToZ/Common/Editor/SkinnedMeshCombiner/SkinnedMeshCombinerCore.cs:68)
JLChnToZ.EditorExtensions.SkinnedMeshCombiner.MeshCombinerWindow.Combine () (at Assets/JLChnToZ/Common/Editor/MeshCombinerWindow.cs:616)
JLChnToZ.EditorExtensions.SkinnedMeshCombiner.MeshCombinerWindow.OnGUI () (at Assets/JLChnToZ/Common/Editor/MeshCombinerWindow.cs:114)
System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <eae584ce26bc40229c1b1aa476bfa589>: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 <eae584ce26bc40229c1b1aa476bfa589>:0)
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) (at <eae584ce26bc40229c1b1aa476bfa589>:0)
UnityEditor.HostView.Invoke (System.String methodName, System.Object obj) (at <1129d3b8df0448079e2ccfb85c3975ef>:0)
UnityEditor.HostView.Invoke (System.String methodName) (at <1129d3b8df0448079e2ccfb85c3975ef>:0)
UnityEditor.HostView.InvokeOnGUI (UnityEngine.Rect onGUIPosition, UnityEngine.Rect viewRect) (at <1129d3b8df0448079e2ccfb85c3975ef>:0)
UnityEditor.DockArea.DrawView (UnityEngine.Rect viewRect, UnityEngine.Rect dockAreaRect) (at <1129d3b8df0448079e2ccfb85c3975ef>:0)
UnityEditor.DockArea.OldOnGUI () (at <1129d3b8df0448079e2ccfb85c3975ef>:0)
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 <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, UnityEngine.Matrix4x4 worldTransform, UnityEngine.Rect clippingRect, System.Action onGUIHandler, System.Boolean canAffectFocus) (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, System.Action onGUIHandler, System.Boolean canAffectFocus) (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e, System.Boolean canAffectFocus) (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.IMGUIContainer.SendEventToIMGUI (UnityEngine.UIElements.EventBase evt, System.Boolean canAffectFocus) (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.IMGUIContainer.HandleEvent (UnityEngine.UIElements.EventBase evt) (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.CallbackEventHandler.HandleEventAtTargetPhase (UnityEngine.UIElements.EventBase evt) (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.MouseCaptureDispatchingStrategy.DispatchEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.EventDispatcher.ApplyDispatchingStrategies (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel, System.Boolean imguiEventIsInitiallyUsed) (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.EventDispatcher.ProcessEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.EventDispatcher.ProcessEventQueue () (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.EventDispatcher.OpenGate () (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.EventDispatcherGate.Dispose () (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.EventDispatcher.ProcessEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.EventDispatcher.Dispatch (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel, UnityEngine.UIElements.DispatchMode dispatchMode) (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.BaseVisualElementPanel.SendEvent (UnityEngine.UIElements.EventBase e, UnityEngine.UIElements.DispatchMode dispatchMode) (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.UIElementsUtility.DoDispatch (UnityEngine.UIElements.BaseVisualElementPanel panel) (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.UIElements.UIElementsUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr) (at <1c3fb9ac36654b3db61feb0cde09ed40>:0)
UnityEngine.GUIUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr) (at <5290814ab61745a89b1850f41273ab3a>:0)

[JLChnToZ]

After confirm, this is a bug, will fix it in next version.

[JLChnToZ]

I patched in 0.8.1, please update it.
If the problem still exists please re-open this issue.