# Upgraded to 4.22, garbage collection crasch at levelstream

**URL:** <https://forums.unrealengine.com/t/upgraded-to-4-22-garbage-collection-crasch-at-levelstream/454179>\
**Category:** Platform & Builds\
**Tags:** level-loading, level-load, garbage-collection, unreal-engine, crash, UE4, question\
**Created:** [August 21, 2019, 9:56am UTC](https://forums.unrealengine.com/t/upgraded-to-4-22-garbage-collection-crasch-at-levelstream/454179 "2019-08-21T09:56:31Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![carpet200](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@carpet200](https://forums.unrealengine.com/u/carpet200)\
**Post date:** [August 21, 2019, 9:56am UTC](https://forums.unrealengine.com/t/upgraded-to-4-22-garbage-collection-crasch-at-levelstream/454179/1 "2019-08-21T09:56:31Z")

</div>

After upgrading from 4.19 to 4.22 i get this crasch sometimes when i unload and then load levels. I have not tested in a packaged build yet so it may be editor only but i don’t know.

The crasch has something to do with garbage collection and default class objects. The crasch happens randomly when i unload a level and then load another where this object exists in. It’s different class objects that crasches it, this time it was “BP\_Ladder\_Double”.

So, why does it crasch, is it editor only, and what can i do to prevent it?

```
LoginId:7653406f4318e985935c3994a00d6716
EpicAccountId:3b602ab74de742e4b137302f83832a72

Assertion failed: !HasAnyFlags(RF_NeedLoad|RF_NeedPostLoad) [File:D:\Build\++UE4\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\UObjectLinker.cpp] [Line: 105] Detaching from existing linker for ../../../../../../Users/carl_/Documents/Unreal Projects/Carl_Project_C/Content/Blueprints/MovePath/BP_Ladder_Double.uasset while object NavLinkCustomComponent /Engine/Transient.Default__BP_Ladder_Double_C:None needs loaded

UE4Editor_Core!FWindowsErrorOutputDevice::Serialize() [d:\build\++ue4\sync\engine\source\runtime\core\private\windows\windowserroroutputdevice.cpp:79]
UE4Editor_Core!FOutputDevice::LogfImpl() [d:\build\++ue4\sync\engine\source\runtime\core\private\misc\outputdevice.cpp:71]
UE4Editor_Core!AssertFailedImplV() [d:\build\++ue4\sync\engine\source\runtime\core\private\misc\assertionmacros.cpp:101]
UE4Editor_Core!FDebug::CheckVerifyFailedImpl() [d:\build\++ue4\sync\engine\source\runtime\core\private\misc\assertionmacros.cpp:439]
UE4Editor_CoreUObject!DispatchCheckVerify<void,<lambda_695fdc4b410127af34cdffd68e8f98cf> >() [d:\build\++ue4\sync\engine\source\runtime\core\public\misc\assertionmacros.h:161]
UE4Editor_CoreUObject!UObject::SetLinker() [d:\build\++ue4\sync\engine\source\runtime\coreuobject\private\uobject\uobjectlinker.cpp:105]
UE4Editor_CoreUObject!UObject::BeginDestroy() [d:\build\++ue4\sync\engine\source\runtime\coreuobject\private\uobject\obj.cpp:774]
UE4Editor_CoreUObject!UObject::ConditionalBeginDestroy() [d:\build\++ue4\sync\engine\source\runtime\coreuobject\private\uobject\obj.cpp:975]
UE4Editor_CoreUObject!UnhashUnreachableObjects() [d:\build\++ue4\sync\engine\source\runtime\coreuobject\private\uobject\garbagecollection.cpp:1636]
UE4Editor_CoreUObject!CollectGarbageInternal() [d:\build\++ue4\sync\engine\source\runtime\coreuobject\private\uobject\garbagecollection.cpp:1576]
UE4Editor_CoreUObject!TryCollectGarbage() [d:\build\++ue4\sync\engine\source\runtime\coreuobject\private\uobject\garbagecollection.cpp:1690]
UE4Editor_Engine!UEngine::ConditionalCollectGarbage() [d:\build\++ue4\sync\engine\source\runtime\engine\private\unrealengine.cpp:1248]
UE4Editor_Engine!UWorld::Tick() [d:\build\++ue4\sync\engine\source\runtime\engine\private\leveltick.cpp:1758]
UE4Editor_UnrealEd!UEditorEngine::Tick() [d:\build\++ue4\sync\engine\source\editor\unrealed\private\editorengine.cpp:1437]
UE4Editor_UnrealEd!UUnrealEdEngine::Tick() [d:\build\++ue4\sync\engine\source\editor\unrealed\private\unrealedengine.cpp:403]
UE4Editor!FEngineLoop::Tick() [d:\build\++ue4\sync\engine\source\runtime\launch\private\launchengineloop.cpp:3967]
UE4Editor!GuardedMain() [d:\build\++ue4\sync\engine\source\runtime\launch\private\launch.cpp:168]
UE4Editor!GuardedMainWrapper() [d:\build\++ue4\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:145]
UE4Editor!WinMain() [d:\build\++ue4\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:275]
UE4Editor!__scrt_common_main_seh() [d:\agent\_work\3\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
kernel32
ntdll
```

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<div class="post-metadata">

**Author:** ![carpet200](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@carpet200](https://forums.unrealengine.com/u/carpet200)\
**Post date:** [August 21, 2019, 10:57am UTC](https://forums.unrealengine.com/t/upgraded-to-4-22-garbage-collection-crasch-at-levelstream/454179/2 "2019-08-21T10:57:04Z")

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After compiling the blueprints that crasched it, it seems to work.