# How to debug crashes

**URL:** <https://forums.unrealengine.com/t/how-to-debug-crashes/460528>\
**Category:** Character & Animation\
**Tags:** Blender, unreal-engine, crash, FBX, import, question\
**Created:** [January 13, 2020, 8:13pm UTC](https://forums.unrealengine.com/t/how-to-debug-crashes/460528 "2020-01-13T20:13:47Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![hawke84](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@hawke84](https://forums.unrealengine.com/u/hawke84)\
**Post date:** [January 13, 2020, 8:13pm UTC](https://forums.unrealengine.com/t/how-to-debug-crashes/460528/1 "2020-01-13T20:13:47Z")

</div>

I’m trying to do a very simple FBX import of a simple mesh from Blender with some simple animations, but the import results in a crash (and unfortunately, debugging those is infamously difficult).

I suspect it has something to do with the material looking at the stacktrace…Thing is, if I remove the armature it imports fine. If I keep the armature but remove the animations, it crashes. So is there something with the armature in comination with the material I should be taking care of?

I gave the mesh a very basic plain material, nothing custom. How do you folks deal with crashes like this? Would submitting a bugreport be the fastest way?

Attached the mesh and FBX: link text

**Blender v2.81.16**

**UE v4.24.1**

**OS: MacOS 10.15.2**

> Assertion failed: Resource  
> [File:/Users/build/Build/++UE4/Sync/Engine/Source/Runtime/Apple/MetalRHI/Private/MetalUniformBuffer.cpp]  
> [Line: 142]
> 
> FGenericPlatformMisc::RaiseException(unsigned  
> int) Address = 0x10f9932f7 (filename  
> not found) [in UE4Editor-Core.dylib]  
> FMacErrorOutputDevice::Serialize(char16\_t  
> const\*, ELogVerbosity::Type, FName  
> const&) Address = 0x10faf6ed0  
> (filename not found) [in  
> UE4Editor-Core.dylib]  
> FOutputDevice::LogfImpl(char16\_t  
> const\*, …) Address = 0x10fbf5ae9  
> (filename not found) [in  
> UE4Editor-Core.dylib]  
> AssertFailedImplV(char const\*, char  
> const\*, int, char16\_t const\*,  
> \_\_va\_list\_tag\*) Address = 0x10fb7bd2d (filename not found) [in  
> UE4Editor-Core.dylib]  
> FDebug::CheckVerifyFailedImpl(char  
> const\*, char const\*, int, char16\_t  
> const\*, …) Address = 0x10fb7bbb4  
> (filename not found) [in  
> UE4Editor-Core.dylib]  
> FMetalUniformBuffer::FMetalUniformBuffer(void  
> const\*, FRHIUniformBufferLayout  
> const&, EUniformBufferUsage,  
> EUniformBufferValidation) Address =  
> 0x15735e1da (filename not found) [in  
> UE4Editor-MetalRHI.dylib]  
> FMetalDynamicRHI::RHICreateUniformBuffer(void  
> const\*, FRHIUniformBufferLayout  
> const&, EUniformBufferUsage,  
> EUniformBufferValidation) Address =  
> 0x157365acd (filename not found) [in  
> UE4Editor-MetalRHI.dylib]  
> CreateLocalVFUniformBuffer(FLocalVertexFactory  
> const\*, unsigned int,  
> FColorVertexBuffer\*, int) Address =  
> 0x111defb07 (filename not found) [in  
> UE4Editor-Engine.dylib]  
> FGPUSkinPassthroughVertexFactory::SetData(FLocalVertexFactory::FDataType  
> const&) Address = 0x112560004  
> (filename not found) [in  
> UE4Editor-Engine.dylib]  
> TGPUSkinVertexFactory::CopyDataTypeForPassthroughFactory(FGPUSkinPassthroughVertexFactory\*)  
> Address = 0x111c44b8b (filename not  
> found) [in UE4Editor-Engine.dylib]  
> TGraphTask CreatePassthroughVertexFactory
> 
> > (ERHIFeatureLevel::Type, TArray TDefaultDelete  
> > , TSizedDefaultAllocator\<32\> \>&, TGPUSkinVertexFactory\*)::InitPassthroughGPUSkinVertexFactoryName,  
> > void  
> > CreatePassthroughVertexFactory  
> > (ERHIFeatureLevel::Type, TArray TDefaultDelete  
> > , TSizedDefaultAllocator\<32\> \>&, TGPUSkinVertexFactory\*)::‘lambda’(FRHICommandList&)\>  
> > ::ExecuteTask(TArray \>&,  
> > ENamedThreads::Type) Address =  
> > 0x1125e409f (filename not found) [in  
> > UE4Editor-Engine.dylib]  
> > FNamedTaskThread::ProcessTasksNamedThread(int,  
> > bool) Address = 0x10f950920 (filename  
> > not found) [in UE4Editor-Core.dylib]  
> > FNamedTaskThread::ProcessTasksUntilQuit(int)  
> > Address = 0x10f94f793 (filename not  
> > found) [in UE4Editor-Core.dylib]  
> > RenderingThreadMain(FEvent\*) Address =  
> > 0x1172c5e13 (filename not found) [in  
> > UE4Editor-RenderCore.dylib]  
> > FRenderingThread::Run() Address =  
> > 0x117335ef7 (filename not found) [in  
> > UE4Editor-RenderCore.dylib]  
> > FRunnableThreadPThread::Run() Address  
> > = 0x10fa0d136 (filename not found) [in UE4Editor-Core.dylib]  
> > FRunnableThreadPThread::\_ThreadProc(void\*)  
> > Address = 0x10f9c1011 (filename not  
> > found) [in UE4Editor-Core.dylib]  
> > \_pthread\_start Address = 0x7fff6ea65e65 (filename not found)  
> > [in libsystem\_pthread.dylib]  
> > thread\_start Address = 0x7fff6ea6183b  
> > (filename not found) [in  
> > libsystem\_pthread.dylib]

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<div class="post-metadata">

**Author:** ![hawke84](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@hawke84](https://forums.unrealengine.com/u/hawke84)\
**Post date:** [January 18, 2020, 4:20pm UTC](https://forums.unrealengine.com/t/how-to-debug-crashes/460528/2 "2020-01-18T16:20:11Z")

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If someone runs into it; got some feedback from my bugreport to UE:

> "It looks like this crash will be  
> fixed in the 4.24.2 hotfix (I do not  
> have hotfix ETA)  
> [Unreal Engine Issues and Bug Tracker (UE-86287)](https://issues.unrealengine.com/issue/UE-86287)  
> If you are compiling your engine from  
> source, you can try applying the fix.  
> "