Unreal Engine Issues and Bug Tracker (UE-41774)

Description

Calling Get Material Index node with an invalid slot name will produce a return value of -1. Passing this value to a Get Material node causes the editor to crash.

Steps to Reproduce

Open UE4 Editor (Third Person Template)
Open Third Person Character blueprint
Add Get Material Index (Mesh) node
Set slot name to "Testing"
Pull off of Return Value pin and create Get Material (Mesh) node
Wire Get Material's Return Value pin into Print String node
Wire Print String into Being Play
PIE

Result:
Editor crashes at PIE

Expected:
Get Material Index node warns that slot name is invalid or return value is negative when blueprint is compiled.

Callstack

LoginId:7156c35640f86204e61b8383f45dee17
EpicAccountId:e8c7fa630b6440f69a25a2c64d6c482c

Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\Build\++UE4+Release-4.15+Compile\Sync\Engine\Source\Runtime\Core\Public\Containers/Array.h] [Line: 633] 
Array index out of bounds: -1 from an array of size 0


UE4Editor_Core!FDebug::AssertFailed() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\core\private\misc\assertionmacros.cpp:349]
UE4Editor_Engine!USkinnedMeshComponent::GetMaterial() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\engine\private\components\skinnedmeshcomponent.cpp:705]
UE4Editor_Engine!UPrimitiveComponent::execGetMaterial() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\engine\classes\components\primitivecomponent.h:118]
UE4Editor_CoreUObject!UFunction::Invoke() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\coreuobject\private\uobject\class.cpp:4525]
UE4Editor_CoreUObject!UObject::CallFunction() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:721]
UE4Editor_CoreUObject!UObject::execVirtualFunction() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:2255]
UE4Editor_CoreUObject!UObject::ProcessContextOpcode() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:2149]
UE4Editor_CoreUObject!UObject::execLetObj() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:1984]
UE4Editor_CoreUObject!UObject::ProcessInternal() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:948]
UE4Editor_CoreUObject!UObject::CallFunction() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:845]
UE4Editor_CoreUObject!UObject::execVirtualFunction() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:2255]
UE4Editor_CoreUObject!UObject::ProcessInternal() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:948]
UE4Editor_CoreUObject!UFunction::Invoke() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\coreuobject\private\uobject\class.cpp:4525]
UE4Editor_CoreUObject!UObject::ProcessEvent() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:1318]
UE4Editor_Engine!AActor::ProcessEvent() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\engine\private\actor.cpp:678]
UE4Editor_Engine!AActor::ReceiveBeginPlay()
UE4Editor_Engine!AActor::BeginPlay() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\engine\private\actor.cpp:3129]
UE4Editor_Engine!AActor::DispatchBeginPlay() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\engine\private\actor.cpp:3097]
UE4Editor_Engine!AWorldSettings::NotifyBeginPlay() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\engine\private\worldsettings.cpp:183]
UE4Editor_Engine!AGameStateBase::HandleBeginPlay() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\engine\private\gamestatebase.cpp:177]
UE4Editor_Engine!UWorld::BeginPlay() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\engine\private\world.cpp:3435]
UE4Editor_Engine!UGameInstance::StartPlayInEditorGameInstance() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\engine\private\gameinstance.cpp:338]
UE4Editor_UnrealEd!UEditorEngine::CreatePIEGameInstance() [d:\build\++ue4+release-4.15+compile\sync\engine\source\editor\unrealed\private\playlevel.cpp:3420]
UE4Editor_UnrealEd!UEditorEngine::PlayInEditor() [d:\build\++ue4+release-4.15+compile\sync\engine\source\editor\unrealed\private\playlevel.cpp:2515]
UE4Editor_UnrealEd!UEditorEngine::StartQueuedPlayMapRequest() [d:\build\++ue4+release-4.15+compile\sync\engine\source\editor\unrealed\private\playlevel.cpp:1215]
UE4Editor_UnrealEd!UEditorEngine::Tick() [d:\build\++ue4+release-4.15+compile\sync\engine\source\editor\unrealed\private\editorengine.cpp:1522]
UE4Editor_UnrealEd!UUnrealEdEngine::Tick() [d:\build\++ue4+release-4.15+compile\sync\engine\source\editor\unrealed\private\unrealedengine.cpp:391]
UE4Editor!FEngineLoop::Tick() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:3025]
UE4Editor!GuardedMain() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\launch\private\launch.cpp:166]
UE4Editor!GuardedMainWrapper() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:134]
UE4Editor!WinMain() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:210]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264]
kernel32
ntdll

Have Comments or More Details?

Head over to the existing Questions & Answers thread and let us know what's up.

1	Login to Vote

Fixed

Component	UE - Graphics Features
Affects Versions	4.14.3, 4.15
Target Fix	4.16

Fix Commit	3310155
Main Commit	3357449

Created	Feb 8, 2017
Resolved	Feb 17, 2017
Updated	Apr 27, 2018

Pull Requests

3231 - projectgheist

View Jira Issue

UE-41774

Editor Crashes if GetMaterialIndex is called with an invalid slot name

Editor Crashes if GetMaterialIndex is called with an invalid slot name

Have Comments or More Details?