Unreal Engine Level Crashes while opening

Camokid83 · November 21, 2025, 6:05am

im hoping to get some help resolving this problem. my project opens up fine but when opening up my level that has everything , it ends up crashing. i tried reinstalling the engine and plugins but im still getting the same error. can anyone please help out with this? heres the full crash report , Assertion failed: !Obj->HasAnyFlags(RF_NeedLoad|RF_NeedPostLoad|RF_ClassDefaultObject) || bIsOwnedByCDOOrArchetype [File:D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\UObjectGlobals.cpp] [Line: 3749]
Attempting to replace an object that hasn’t been fully loaded: DynamicMesh /Game/Area1.Area1:PersistentLevel.MCK_Lot_ParkingLot_C_UAID_C87F54CED4F2DCA302_1704900758.ParkingLotComponent.DynamicMesh (Outer=ParkingLotComponent_C /Game/Area1.Area1:PersistentLevel.MCK_Lot_ParkingLot_C_UAID_C87F54CED4F2DCA302_1704900758.ParkingLotComponent, Flags=0x002c3000)

UnrealEditor_Core!FDebug::CheckVerifyFailedImpl2() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Private\Misc\AssertionMacros.cpp:745]
UnrealEditor_CoreUObject!StaticAllocateObject() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\UObjectGlobals.cpp:3744]
UnrealEditor_CoreUObject!StaticConstructObject_Internal() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\UObjectGlobals.cpp:4963]
UnrealEditor_GeometryFramework!NewObject() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Public\UObject\UObjectGlobals.h:1951]
UnrealEditor_GeometryFramework!UDynamicMeshComponent::PostLoad() [D:\build++UE5\Sync\Engine\Source\Runtime\GeometryFramework\Private\Components\DynamicMeshComponent.cpp:127]
UnrealEditor_CoreUObject!UObject::ConditionalPostLoad() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\Obj.cpp:1388]
UnrealEditor_Engine!UBodySetup::PostLoad() [D:\build++UE5\Sync\Engine\Source\Runtime\Engine\Private\PhysicsEngine\BodySetup.cpp:1010]
UnrealEditor_CoreUObject!UObject::ConditionalPostLoad() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\Obj.cpp:1388]
UnrealEditor_CoreUObject!FAsyncPackage2::ExecuteDeferredPostLoadLinkerLoadPackageExports() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading2.cpp:7566]
UnrealEditor_CoreUObject!FAsyncPackage2::Event_DeferredPostLoadExportBundle() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading2.cpp:9551]
UnrealEditor_CoreUObject!FEventLoadNode2::Execute() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading2.cpp:5979]
UnrealEditor_CoreUObject!FAsyncLoadEventQueue2::ExecuteSyncLoadEvents() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading2.cpp:6186]
UnrealEditor_CoreUObject!FAsyncLoadingThread2::ProcessLoadedPackagesFromGameThread() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading2.cpp:9935]
UnrealEditor_CoreUObject!FAsyncLoadingThread2::TickAsyncLoadingFromGameThread() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading2.cpp:10194]
UnrealEditor_CoreUObject!FAsyncLoadingThread2::FlushLoading() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading2.cpp:11909]
UnrealEditor_CoreUObject!FlushAsyncLoading() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncPackageLoader.cpp:354]
UnrealEditor_Engine!FWorldPartitionLoadingContext::FDeferred::~FDeferred'::8’::<lambda_1>::operator()() [D:\build++UE5\Sync\Engine\Source\Runtime\Engine\Private\WorldPartition\WorldPartitionHandle.cpp:178]
UnrealEditor_Engine!FWorldPartitionLoadingContext::FDeferred::~FDeferred() [D:\build++UE5\Sync\Engine\Source\Runtime\Engine\Private\WorldPartition\WorldPartitionHandle.cpp:201]
UnrealEditor_Engine!IWorldPartitionActorLoaderInterface::ILoaderAdapter::RefreshLoadedState() [D:\build++UE5\Sync\Engine\Source\Runtime\Engine\Private\WorldPartition\WorldPartitionActorLoaderInterface.cpp:190]
UnrealEditor_Engine!UWorldPartition::LoadLastLoadedRegions() [D:\build++UE5\Sync\Engine\Source\Runtime\Engine\Private\WorldPartition\WorldPartition.cpp:2378]
UnrealEditor_Engine!UWorldPartition::LoadLastLoadedRegions() [D:\build++UE5\Sync\Engine\Source\Runtime\Engine\Private\WorldPartition\WorldPartition.cpp:2390]
UnrealEditor_Engine!UWorldPartition::Initialize() [D:\build++UE5\Sync\Engine\Source\Runtime\Engine\Private\WorldPartition\WorldPartition.cpp:845]
UnrealEditor_Engine!ULevel::OnLevelLoaded() [D:\build++UE5\Sync\Engine\Source\Runtime\Engine\Private\Level.cpp:3501]
UnrealEditor_Engine!UWorld::InitWorld() [D:\build++UE5\Sync\Engine\Source\Runtime\Engine\Private\World.cpp:2519]
UnrealEditor_UnrealEd!UEditorEngine::Map_Load() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorServer.cpp:2667]
UnrealEditor_UnrealEd!UEditorEngine::HandleMapCommand() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorServer.cpp:6227]
UnrealEditor_UnrealEd!UEditorEngine::Exec_Editor() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorServer.cpp:5688]
UnrealEditor_Core!FExec::Exec() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Private\Misc\Exec.cpp:18]
UnrealEditor_Engine!UEngine::Exec() [D:\build++UE5\Sync\Engine\Source\Runtime\Engine\Private\UnrealEngine.cpp:5213]
UnrealEditor_UnrealEd!UUnrealEdEngine::Exec() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\UnrealEdSrv.cpp:662]
UnrealEditor_UnrealEd!FEditorFileUtils::LoadMap() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\FileHelpers.cpp:3306]
UnrealEditor_EngineAssetDefinitions!UAssetDefinition_World::OpenAssets() [D:\build++UE5\Sync\Engine\Plugins\Editor\EngineAssetDefinitions\Source\Private\AssetDefinition_World.cpp:68]
UnrealEditor_AssetTools!FAssetDefinitionProxy::OpenAssetEditor() [D:\build++UE5\Sync\Engine\Source\Developer\AssetTools\Private\AssetTools.cpp:260]
UnrealEditor_UnrealEd!UAssetEditorSubsystem::OpenEditorForAsset() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\Subsystems\AssetEditorSubsystem.cpp:586]
UnrealEditor_UnrealEd!UAssetEditorSubsystem::OpenEditorForAssets_Advanced() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\Subsystems\AssetEditorSubsystem.cpp:655]
UnrealEditor_UnrealEd!UAssetEditorSubsystem::OpenEditorForAssets() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\Subsystems\AssetEditorSubsystem.cpp:780]
UnrealEditor_ContentBrowserAssetDataSource!ContentBrowserAssetData::EditOrPreviewAssetFileItems() [D:\build++UE5\Sync\Engine\Plugins\Editor\ContentBrowser\ContentBrowserAssetDataSource\Source\ContentBrowserAssetDataSource\Private\ContentBrowserAssetDataCore.cpp:429]
UnrealEditor_ContentBrowserAssetDataSource!ContentBrowserAssetData::EditOrPreviewItems() [D:\build++UE5\Sync\Engine\Plugins\Editor\ContentBrowser\ContentBrowserAssetDataSource\Source\ContentBrowserAssetDataSource\Private\ContentBrowserAssetDataCore.cpp:474]
UnrealEditor_ContentBrowserAssetDataSource!UContentBrowserAssetDataSource::BulkEditItems() [D:\build++UE5\Sync\Engine\Plugins\Editor\ContentBrowser\ContentBrowserAssetDataSource\Source\ContentBrowserAssetDataSource\Private\ContentBrowserAssetDataSource.cpp:2759]
UnrealEditor_ContentBrowser!SContentBrowser::OnItemsActivated() [D:\build++UE5\Sync\Engine\Source\Editor\ContentBrowser\Private\SContentBrowser.cpp:3236]
UnrealEditor_ContentBrowser!TBaseSPMethodDelegateInstance<0,SContentBrowser,1,void __cdecl(TArrayView<FContentBrowserItem const ,int>,enum EAssetTypeActivationMethod::Type),FDefaultDelegateUserPolicy>::Execute() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:308]
UnrealEditor_ContentBrowser!SAssetView::OnListMouseButtonDoubleClick() [D:\build++UE5\Sync\Engine\Source\Editor\ContentBrowser\Private\SAssetView.cpp:5733]
UnrealEditor_ContentBrowser!TBaseSPMethodDelegateInstance<0,SAssetView,1,void __cdecl(TSharedPtr<FAssetViewItem,1>),FDefaultDelegateUserPolicy>::ExecuteIfSafe() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:325]
UnrealEditor_ContentBrowser!TDelegate<void __cdecl(TSharedPtr<FAssetViewItem,1>),FDefaultDelegateUserPolicy>::ExecuteIfBound() [D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateSignatureImpl.inl:631]
UnrealEditor_ContentBrowser!SListView<TSharedPtr<FAssetViewItem,1> >::Private_OnItemDoubleClicked() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Public\Widgets\Views\SListView.h:1165]
UnrealEditor_ContentBrowser!STableRow<TSharedPtr<FAssetViewItem,1> >::OnMouseButtonDoubleClick() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Public\Widgets\Views\STableRow.h:446]
UnrealEditor_Slate!FEventRouter::Route<FReply,FEventRouter::FBubblePolicy,FPointerEvent,FSlateApplication::RoutePointerDoubleClickEvent'::2’::<lambda_1> >() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:459]
UnrealEditor_Slate!FSlateApplication::RoutePointerDoubleClickEvent() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5966]
UnrealEditor_Slate!FSlateApplication::ProcessMouseButtonDoubleClickEvent() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5951]
UnrealEditor_Slate!FSlateApplication::OnMouseDoubleClick() [D:\build++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5914]
UnrealEditor_ApplicationCore!FWindowsApplication::ProcessDeferredMessage() [D:\build++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:3378]
UnrealEditor_ApplicationCore!FWindowsApplication::DeferMessage() [D:\build++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:3903]
UnrealEditor_ApplicationCore!FWindowsApplication::ProcessMessage() [D:\build++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2311]
UnrealEditor_ApplicationCore!FWindowsApplication::AppWndProc() [D:\build++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2134]
user32
user32
UnrealEditor_ApplicationCore!FWindowsPlatformApplicationMisc::PumpMessages() [D:\build++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsPlatformApplicationMisc.cpp:153]
UnrealEditor!FEngineLoop::Tick() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:5753]
UnrealEditor!GuardedMain() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:190]
UnrealEditor!GuardedMainWrapper() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:123]
UnrealEditor!LaunchWindowsStartup() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:277]
UnrealEditor!WinMain() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:334]
UnrealEditor!__scrt_common_main_seh() [D:\a_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
kernel32
ntdll

brs-sebascova · November 21, 2025, 3:27pm

Hello there @Camokid83!

Checking through your log, the crash is referring to a very specific object:

Assertion failed: !Obj->HasAnyFlags(RF_NeedLoad|RF_NeedPostLoad|RF_ClassDefaultObject) || bIsOwnedByCDOOrArchetype [File:D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\UObjectGlobals.cpp] [Line: 3749]

Attempting to replace an object that hasn’t been fully loaded: DynamicMesh /Game/Area1.Area1:PersistentLevel.MCK_Lot_ParkingLot_C_UAID_C87F54CED4F2DCA302_1704900758.ParkingLotComponent.DynamicMesh

This means there’s a problem with an element tied to MCK_Lot_ParkingLot_C, could be it’s mesh, it’s blueprint, or another dependency. Per the rest of the log, this seems to be the sole cultrip. Meaning, our first test is to load the map without said asset.

So, open the project, create an empty level, and try to load only the affected asset from there. If UE crashes, we have confirmed that the asset is the problem. From there, use the Outliner to either disable or delete the actor. If you need to keep the actor, try reloading it’s blueprint, and look for any broken references between. You can also replace it’s model with a simple, static mesh.

Once completed, you need to implement “Fix Up Redirectors” and “Validate Assets” in the project. If the problem persists even with the asset fixed or removed, the other possibility in the log, is a loading conflict with Geometry Framework. To ensure this is not the case, go to Edit > Plugins and check that “Modeling Tools Editor Mode” and “Geometry Script” are enabled. If they are, please disable them, restart the engine, and enable them again, to reset their dependencies.

Finally, after all these changes, there could be traces of corruption left in your cache. Go to your project’s directory, and delete folders DerivedDataCache, Intermediate, and Saved, then re-open UE, and allow it to rebuild. If the issue remains active, please send a new log extract, and we will continue investigating. Good luck!