[CrashReport] UE4Editor-MetalRHI.dylib!TranslatePrimitiveType()

[2017.11.15-20.09.54:885][537]TextureStreamingBuild: Display: Compiling optional shaders took 0.003 seconds.
[2017.11.15-20.09.55:135][537]LogSavePackage: Save=19.14ms
[2017.11.15-20.09.55:135][537]LogSavePackage: Moving '../../../../../../***/Desktop/***/Barn/Saved/Test_VertPaint1CD5800EC244DAD93ED2608528133296.tmp' to '../../../../../../***/Desktop/***/Barn/Content/Barn/Materials/Test_VertPaint.uasset'
[2017.11.15-20.09.55:136][537]LogSavePackage: Display: Finished SavePackage ../../../../../../***/Desktop/***/Barn/Content/Barn/Materials/Test_VertPaint.uasset
[2017.11.15-20.11.18:476][707]LogMac: Error: appError called: Assertion failed:  [File:/Users/build/Build/++UE4+Release-4.18+Compile/Sync/Engine/Source/Runtime/Apple/MetalRHI/Private/MetalCommands.cpp] [Line: 50] 
Unsupported primitive type 16

[2017.11.15-20.11.18:483][707]LogMac: === Critical error: ===
SIGSEGV: invalid attempt to access memory at address 0x3

[2017.11.15-20.11.18:483][707]LogMac: 0x0a6e499b UE4Editor-Core.dylib!FGenericPlatformMisc::RaiseException(unsigned int)   [UnknownFile]) 
0x10523c09 UE4Editor-ApplicationCore.dylib!FMacErrorOutputDevice::Serialize(wchar_t const*, ELogVerbosity::Type, FName const&)   [UnknownFile]) 
0x0a992c9d UE4Editor-Core.dylib!FOutputDevice::Logf(wchar_t const*, ...)   [UnknownFile]) 
0x0a908efb UE4Editor-Core.dylib!FDebug::AssertFailed(char const*, char const*, int, wchar_t const*, ...)   [UnknownFile]) 
0x2e030467 UE4Editor-MetalRHI.dylib!TranslatePrimitiveType(unsigned int)   [UnknownFile]) 
0x2e05a03a UE4Editor-MetalRHI.dylib!FMetalRenderPass::DrawIndexedPrimitive(id<MTLBuffer>, unsigned int, unsigned int, int, unsigned int, unsigned int, unsigned int, unsigned int, unsigned int)   [UnknownFile]) 
0x2e03906a UE4Editor-MetalRHI.dylib!FMetalRHICommandContext::RHIDrawIndexedPrimitive(FRHIIndexBuffer*, unsigned int, int, unsigned int, unsigned int, unsigned int, unsigned int, unsigned int)   [UnknownFile]) 
0x19ffa8b2 UE4Editor-Renderer.dylib!FMeshDrawingPolicy::DrawMesh(FRHICommandList&, FMeshBatch const&, int, bool) const   [UnknownFile]) 
0x19f559bc UE4Editor-Renderer.dylib!FDepthDrawingPolicyFactory::DrawMesh(FRHICommandList&, FViewInfo const&, FDepthDrawingPolicyFactory::ContextType, FMeshBatch const&, unsigned long long const&, FDrawingPolicyRenderState const&, bool, FPrimitiveSceneProxy const*, FHitProxyId, bool, bool)   [UnknownFile]) 
0x19f56ca3 UE4Editor-Renderer.dylib!FDeferredShadingSceneRenderer::RenderPrePassViewDynamic(FRHICommandList&, FViewInfo const&, FDrawingPolicyRenderState const&)   [UnknownFile]) 
0x19f577ad UE4Editor-Renderer.dylib!FDeferredShadingSceneRenderer::RenderPrePassView(FRHICommandList&, FViewInfo const&)   [UnknownFile]) 
0x19f4a5a2 UE4Editor-Renderer.dylib!FDeferredShadingSceneRenderer::RenderPrePass(FRHICommandListImmediate&, TFunctionRef<void ()>)   [UnknownFile]) 
0x19f3b818 UE4Editor-Renderer.dylib!FDeferredShadingSceneRenderer::Render(FRHICommandListImmediate&)   [UnknownFile]) 
0x1a678164 UE4Editor-Renderer.dylib!FRendererModule::BeginRenderingViewFamily(FCanvas*, FSceneViewFamily*)::EURCMacro_FDrawSceneCommand::DoTask(ENamedThreads::Type, TRefCountPtr<FGraphEvent> const&)   [UnknownFile]) 
0x1a6e9baa UE4Editor-Renderer.dylib!TGraphTask<FRendererModule::BeginRenderingViewFamily(FCanvas*, FSceneViewFamily*)::EURCMacro_FDrawSceneCommand>::ExecuteTask(TArray<FBaseGraphTask*, FDefaultAllocator>&, ENamedThreads::Type)   [UnknownFile]) 
0x0a700f1c UE4Editor-Core.dylib!FNamedTaskThread::ProcessTasksNamedThread(int, bool)   [UnknownFile]) 
0x0a6fffc8 UE4Editor-Core.dylib!FNamedTaskThread::ProcessTasksUntilQuit(int)   [UnknownFile]) 
0x0a6fc0ae UE4Editor-Core.dylib!FTaskGraphImplementation::ProcessThreadUntilRequestReturn(ENamedThreads::Type)   [UnknownFile]) 
0x101752a1 UE4Editor-RenderCore.dylib!RenderingThreadMain(FEvent*)   [UnknownFile]) 
0x10189d17 UE4Editor-RenderCore.dylib!FRenderingThread::Run()   [UnknownFile]) 
0x0a77527e UE4Editor-Core.dylib!FRunnableThreadPThread::Run()   [UnknownFile]) 
0x0a71ffc7 UE4Editor-Core.dylib!FRunnableThreadPThread::_ThreadProc(void*)   [UnknownFile]) 
0x6da3c6c1 libsystem_pthread.dylib!_pthread_body()   [UnknownFile]) 
0x6da3c56d libsystem_pthread.dylib!_pthread_body()   [UnknownFile]) 
0x6da3bc5d libsystem_pthread.dylib!thread_start()   [UnknownFile]) 

SEGV_MAPERR at 0x3

UE4Editor-MetalRHI.dylib!TranslatePrimitiveType()
UE4Editor-MetalRHI.dylib!FMetalRenderPass::DrawIndexedPrimitive()
UE4Editor-MetalRHI.dylib!FMetalRHICommandContext::RHIDrawIndexedPrimitive()
UE4Editor-Renderer.dylib!FMeshDrawingPolicy::DrawMesh()
UE4Editor-Renderer.dylib!FDepthDrawingPolicyFactory::DrawMesh()
UE4Editor-Renderer.dylib!FDeferredShadingSceneRenderer::RenderPrePassViewDynamic()
UE4Editor-Renderer.dylib!FDeferredShadingSceneRenderer::RenderPrePassView()
UE4Editor-Renderer.dylib!FDeferredShadingSceneRenderer::RenderPrePass(FRHICommandListImmediate&, TFunctionRef<void()
UE4Editor-Renderer.dylib!FDeferredShadingSceneRenderer::Render()
UE4Editor-Renderer.dylib!FRendererModule::BeginRenderingViewFamily(FCanvas*, FSceneViewFamily*)::EURCMacro_FDrawSceneCommand::DoTask()
UE4Editor-Renderer.dylib!TGraphTask<FRendererModule::BeginRenderingViewFamily(FCanvas*, FSceneViewFamily*)::EURCMacro_FDrawSceneCommand>::ExecuteTask()
UE4Editor-Core.dylib!FNamedTaskThread::ProcessTasksNamedThread()
UE4Editor-Core.dylib!FNamedTaskThread::ProcessTasksUntilQuit()
UE4Editor-Core.dylib!FTaskGraphImplementation::ProcessThreadUntilRequestReturn()
UE4Editor-RenderCore.dylib!RenderingThreadMain()
UE4Editor-RenderCore.dylib!FRenderingThread::Run()
UE4Editor-Core.dylib!FRunnableThreadPThread::Run()
UE4Editor-Core.dylib!FRunnableThreadPThread::_ThreadProc()
libsystem_pthread.dylib!<Unknown>
libsystem_pthread.dylib!<Unknown>
libsystem_pthread.dylib!<Unknown>