Attempting to procedurally create SplineMeshComponents along the spline of a SplineComponent via a derived SplineComponent class's constructor causes the project to crash. It runs into an ensure message "AttachToComponent when called from a constructor cannot weld simulated bodies. Consider calling SetupAttachment directly instead." in the USceneComponent::AttachToComponent function.
Tested in 4.19.2 (CL - 4033788), 4.20.2 (CL - 4306349), 4.21 (CL - 4305553)
Expected: The Project would load properly and allow the derived SplineComponent class to be added to a Blueprint Actor class
Result: The Project encounters a crash when opening the project via the UProject file and triggers a breakpoint in the Visual Studio solution
LoginId:5964f8f84766f4b976277180442869c1
EpicAccountId:2baa9d521a314b24b2efea04e88261b2
Fatal error: [Link Removed] [Line: 3729] Illegal default subobject name: None
UE4Editor_Core!FDebug::AssertFailed() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\core\private\misc\assertionmacros.cpp:419]
UE4Editor_CoreUObject!FObjectInitializer::CreateDefaultSubobject() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:3729]
UE4Editor_CoreUObject!UObject::CreateDefaultSubobject() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\coreuobject\private\uobject\obj.cpp:105]
UE4Editor_SplineMeshes!UMySplineComponent::UMySplineComponent() [e:\epic\unreal projects\splinemeshes\source\splinemeshes\mysplinecomponent.cpp:14]
UE4Editor_CoreUObject!UClass::CreateDefaultObject() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\coreuobject\private\uobject\class.cpp:2749]
UE4Editor_CoreUObject!UObjectLoadAllCompiledInDefaultProperties() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectbase.cpp:821]
UE4Editor_CoreUObject!ProcessNewlyLoadedUObjects() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectbase.cpp:895]
UE4Editor_CoreUObject!TBaseStaticDelegateInstance<void __cdecl(void)>::ExecuteIfSafe() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:788]
UE4Editor_Core!TBaseMulticastDelegate<void>::Broadcast() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\core\public\delegates\delegatesignatureimpl.inl:937]
UE4Editor_Core!FModuleManager::LoadModuleWithFailureReason() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\core\private\modules\modulemanager.cpp:487]
UE4Editor_Projects!FModuleDescriptor::LoadModulesForPhase() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\projects\private\moduledescriptor.cpp:484]
UE4Editor_Projects!FProjectManager::LoadModulesForProject() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\projects\private\projectmanager.cpp:69]
UE4Editor!FEngineLoop::LoadStartupModules() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:2610]
UE4Editor!FEngineLoop::PreInit() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:2027]
UE4Editor!GuardedMain() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\launch\private\launch.cpp:127]
UE4Editor!GuardedMainWrapper() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:144]
UE4Editor!WinMain() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:223]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:253]
kernel32
ntdll
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