Unreal Engine Issues

UE-118707

Crash when baking materials for some skeletal meshes (like those found in Epic's Car Configurator project)

Crash when baking materials for some skeletal meshes (like those found in Epic's Car Configurator project)

Description

FMeshMergeHelpers::RetrieveMesh crashes when trying to prep some skeletal meshes for material baking.

Steps to Reproduce
  1. Download and open "Car Configurator" project in Unreal Editor from marketplace ([Link Removed]).
  2. In Content Browser, search for "SK_Convertible_Top" and double click on the Skeletal Mesh asset to open it in an editor window called "SK_Convertible_Top".
  3. In the toolbar of window "SK_Convertible_Top", click "Bake out Materials" to open a dialog window called "Material Baking Options".
  4. In "Bake out Materials" window, click Confirm.Edit Steps to Reproduce
     
Callstack
Assertion failed: (Index >= 0) & (Index < ArrayNum) File:D:\Build&#43;+UE4\Sync\Engine\Source\Runtime\Core\Public\Containers/Array.h 
[Line: 674] Array index out of bounds: 32 from an array of size 32 UE4Editor_Core!AssertFailedImplV() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Private\Misc\AssertionMacros.cpp:104] UE4Editor_Core!FDebug::CheckVerifyFailedImpl() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Private\Misc\AssertionMacros.cpp:461] UE4Editor_MeshMergeUtilities!DispatchCheckVerify<void,<lambda_b5c14ef3884adafb7fe831c17abccdec> >() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Public\Misc\AssertionMacros.h:165] UE4Editor_MeshMergeUtilities!FMeshMergeHelpers::RetrieveMesh() 
[D:\Build\++UE4\Sync\Engine\Source\Developer\MeshMergeUtilities\Private\MeshMergeHelpers.cpp:332] UE4Editor_MeshMergeUtilities!FMeshMergeUtilities::BakeMaterialsForComponent() 
[D:\Build\++UE4\Sync\Engine\Source\Developer\MeshMergeUtilities\Private\MeshMergeUtilities.cpp:145] UE4Editor_MeshMergeUtilities!FMeshMergeUtilities::BakeMaterialsForComponent() 
[D:\Build\++UE4\Sync\Engine\Source\Developer\MeshMergeUtilities\Private\MeshMergeUtilities.cpp:459] UE4Editor_MeshMergeUtilities!<lambda_747c8298733ede9d136621237275d741>::operator()() 
[D:\Build\++UE4\Sync\Engine\Source\Developer\MeshMergeUtilities\Private\MeshMergeEditorExtensions.cpp:113] UE4Editor_MeshMergeUtilities!TBaseFunctorDelegateInstance<void _cdecl(FToolMenuContext const &),FDefaultDelegateUserPolicy,<lambda_747c8298733ede9d136621237275d741> >::ExecuteIfSafe() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:838] UE4Editor_ToolMenus!TBaseFunctorDelegateInstance<void __cdecl(void),FDefaultDelegateUserPolicy,<lambda_fccc1bd4ef83d8f2198f8e70891f6d41> >::ExecuteIfSafe() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:839] UE4Editor_Slate!SToolBarButtonBlock::OnClicked() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Slate\Private\Framework\MultiBox\SToolBarButtonBlock.cpp:308] UE4Editor_Slate!TBaseSPMethodDelegateInstance<0,SToolBarButtonBlock,0,FReply __cdecl(void),FDefaultDelegateUserPolicy>::Execute() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:290] UE4Editor_Slate!SButton::ExecuteOnClick() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Slate\Private\Widgets\Input\SButton.cpp:385] UE4Editor_Slate!SButton::OnMouseButtonUp() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Slate\Private\Widgets\Input\SButton.cpp:304] UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_cc5aea9e7377b04ce85c30c65ec3889b> >() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:378] UE4Editor_Slate!FSlateApplication::RoutePointerUpEvent() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:4815] UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5356] UE4Editor_Slate!FSlateApplication::OnMouseUp() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5321] UE4Editor_ApplicationCore!FWindowsApplication::ProcessDeferredMessage() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2178] UE4Editor_ApplicationCore!FWindowsApplication::DeferMessage() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2642] UE4Editor_ApplicationCore!FWindowsApplication::ProcessMessage() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:1046] UE4Editor_ApplicationCore!FWindowsApplication::AppWndProc() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:878] user32 user32 UE4Editor_ApplicationCore!FWindowsPlatformApplicationMisc::PumpMessages() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsPlatformApplicationMisc.cpp:130] UE4Editor!FEngineLoop::Tick() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:4748] UE4Editor!GuardedMain() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:169] UE4Editor!GuardedMainWrapper() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:137] UE4Editor!WinMain() 
[D:\Build\++UE4\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:268] UE4Editor!_scrt_common_main_seh() 
[d:\agent\_work\5\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288] kernel32 ntdll

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Fixed
ComponentzComponent - Archive
Affects Versions4.26.2
Target Fix4.27
Fix Commit16726879
Release Commit16726879
CreatedJun 22, 2021
ResolvedJun 23, 2021
UpdatedFeb 24, 2026
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