Editor Crashes when attempting to copy/paste nodes in Material Editor

UPDATE:
1/8/2015

Crash Reporter: [Link Removed]
Callstack:
<unknown module>! KERNELBASE!RaiseException()
<unknown module>! UE4Editor_Core!FOutputDeviceWindowsError::Serialize()
<unknown module>! UE4Editor_Core!FMsg::Logf__VA()
<unknown module>! UE4Editor_Renderer!FMaterialShader::SetParameters<FRHIVertexShader * __ptr64>()
<unknown module>! UE4Editor_Renderer!TBasePassVertexShaderBaseType<FNoLightMapPolicy>::SetParameters()
<unknown module>! UE4Editor_Renderer!TBasePassDrawingPolicy<FNoLightMapPolicy>::SetSharedState()
<unknown module>! UE4Editor_Renderer!FDrawBasePassDynamicMeshAction::Process<FNoLightMapPolicy>()
<unknown module>! UE4Editor_Renderer!ProcessBasePassMesh<FDrawBasePassDynamicMeshAction>()
<unknown module>! UE4Editor_Renderer!FBasePassOpaqueDrawingPolicyFactory::DrawDynamicMesh()
<unknown module>! UE4Editor_Renderer!TDynamicPrimitiveDrawer<FBasePassOpaqueDrawingPolicyFactory>::DrawMesh()
<unknown module>! UE4Editor_Engine!DrawRichMesh()
<unknown module>! UE4Editor_Engine!FStaticMeshSceneProxy::DrawDynamicElements()
<unknown module>! UE4Editor_Renderer!FDeferredShadingSceneRenderer::RenderBasePassDynamicData()
<unknown module>! UE4Editor_Renderer!FDeferredShadingSceneRenderer::RenderBasePass()
<unknown module>! UE4Editor_Renderer!FDeferredShadingSceneRenderer::Render()
<unknown module>! UE4Editor_Renderer!RenderViewFamily_RenderThread()
<unknown module>! UE4Editor_Renderer!TGraphTask<`FRendererModule::BeginRenderingViewFamily'::`11'::EURCMacro_FDrawSceneCommand>::ExecuteTask()
<unknown module>! UE4Editor_Core!FTaskThread::ProcessTasks()
<unknown module>! UE4Editor_Core!FTaskThread::ProcessTasksUntilQuit()
<unknown module>! UE4Editor_RenderCore!RenderingThreadMain()
<unknown module>! UE4Editor_RenderCore!FRenderingThread::Run()
<unknown module>! UE4Editor_Core!FRunnableThreadWin::Run()
<unknown module>! UE4Editor_Core!FRunnableThreadWin::GuardedRun()
<unknown module>! kernel32!BaseThreadInitThunk()
<unknown module>! ntdll!RtlUserThreadStart()
===================================================
UPDATE:

Reproduced Internally
Date Reproduced - 1/7/2015
Engine Version - 4.6.1-2386410

Editor crashed multiple times, even when copying/pasting a single texture sample node.

===================================================

Editor crashes when attempting to copy/paste nodes in material editor. According to users, this occurs both when copying in same material and when copying between materials using Ctrl+c/Ctrl+v

Callstack:

<unknown module>! KERNELBASE!RaiseException()
<unknown module>! UE4Editor_Core!FOutputDeviceWindowsError::Serialize()
<unknown module>! UE4Editor_Core!FMsg::Logf__VA()
<unknown module>! UE4Editor_Renderer!FMaterialShader::SetParameters<FRHIVertexShader * __ptr64>()
<unknown module>! UE4Editor_Renderer!TBasePassVertexShaderBaseType<FNoLightMapPolicy>::SetParameters()
<unknown module>! UE4Editor_Renderer!TBasePassDrawingPolicy<FNoLightMapPolicy>::SetSharedState()
<unknown module>! UE4Editor_Renderer!FDrawBasePassDynamicMeshAction::Process<FNoLightMapPolicy>()
<unknown module>! UE4Editor_Renderer!ProcessBasePassMesh<FDrawBasePassDynamicMeshAction>()
<unknown module>! UE4Editor_Renderer!FBasePassOpaqueDrawingPolicyFactory::DrawDynamicMesh()
<unknown module>! UE4Editor_Renderer!TDynamicPrimitiveDrawer<FBasePassOpaqueDrawingPolicyFactory>::DrawMesh()
<unknown module>! UE4Editor_Engine!DrawRichMesh()
<unknown module>! UE4Editor_Engine!FStaticMeshSceneProxy::DrawDynamicElements()
<unknown module>! UE4Editor_Renderer!FDeferredShadingSceneRenderer::RenderBasePassDynamicData()
<unknown module>! UE4Editor_Renderer!FDeferredShadingSceneRenderer::RenderBasePass()
<unknown module>! UE4Editor_Renderer!FDeferredShadingSceneRenderer::Render()
<unknown module>! UE4Editor_Renderer!RenderViewFamily_RenderThread()
<unknown module>! UE4Editor_Renderer!TGraphTask<`FRendererModule::BeginRenderingViewFamily'::`11'::EURCMacro_FDrawSceneCommand>::ExecuteTask()
<unknown module>! UE4Editor_Core!FTaskThread::ProcessTasks()
<unknown module>! UE4Editor_Core!FTaskThread::ProcessTasksUntilQuit()
<unknown module>! UE4Editor_RenderCore!RenderingThreadMain()
<unknown module>! UE4Editor_RenderCore!FRenderingThread::Run()
<unknown module>! UE4Editor_Core!FRunnableThreadWin::Run()
<unknown module>! UE4Editor_Core!FRunnableThreadWin::GuardedRun()
<unknown module>! kernel32!BaseThreadInitThunk()
<unknown module>! ntdll!RtlUserThreadStart()

Crash Reporter:
[Link Removed]

[Not reproduced internally]
1. Open Editor (any project)
2. Open any material
3. Select multiple nodes by LMB + drag mouse.
4. Ctrl+C to copy nodes

5. Ctrl+V to paste nodes