Landscape + Foliage bug: Manually deleted InstancedFoliageActors remain in memory, causes crashes whenever editing foliage.

Rosy · June 19, 2023, 4:30pm

I have a serious issue with my landscapes, that being that I have in the past manually deleted InstancedFoliageActors from the outliner, but doing so does not remove them from memory and the landscape still remembers the deleted asset.

Because of this, if I try to paint foliage in a landscape region which has had deleted InstanceFoliageActors on it previously, the editor crashes with an error code like this:

Assertion failed: !IsValidChecked(ExistingActor) [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\ActorPartition\ActorPartitionSubsystem.cpp] [Line: 280]

UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Foliage
UnrealEditor_FoliageEdit
UnrealEditor_FoliageEdit
UnrealEditor_FoliageEdit
UnrealEditor_FoliageEdit
UnrealEditor_FoliageEdit
UnrealEditor_UnrealEd
UnrealEditor_UnrealEd
UnrealEditor_UnrealEd
UnrealEditor_UnrealEd
UnrealEditor_UnrealEd
UnrealEditor_UnrealEd
UnrealEditor_Engine
UnrealEditor_Slate
UnrealEditor_Slate
UnrealEditor_Slate
UnrealEditor_Slate
UnrealEditor_Slate
UnrealEditor_ApplicationCore
UnrealEditor_ApplicationCore
UnrealEditor_ApplicationCore
UnrealEditor_ApplicationCore
user32
user32
InkObj
atlthunk
user32
user32
UnrealEditor_ApplicationCore
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
kernel32
ntdll

I believe that the first line of this shows that the editor is looking for an InstancedFoliageActor which no longer exists.

Looking around the internet, I have found many other people with this issue but no solution is out there to my knowledge other than “Port assets to another project and start over.”

I’ve got quite a lot of time put into in my game’s environment, and as such I am not particularly willing to restart it. I’m willing to do anything to resolve this issue, no matter how strangely technical it may get.

If anyone can figure out what’s up here I will actually literally be eternally grateful.

3dRaven · June 19, 2023, 4:50pm

Have you tried deleting temp folders and rebuilding your project?

Rosy · June 19, 2023, 5:18pm

Yes, I have, and unfortunately it doesn’t fix or change the issue.

Rosy · June 19, 2023, 5:28pm

I’ve found an extra bit of info, but not a fix.

If you open your level and unload all foliage, place foliage somewhere, and reload all your foliage you will find that you can place foliage in any region that previously had no foliage or was the region that you placed foliage in at the start.

Unfortunately, this will also delete any foliage in the unloaded region you placed foliage in, and if you try to place foliage in any region which does have foliage, the editor will crash.

3dRaven · June 19, 2023, 5:49pm

It seems to be an error regarding world partition and not specifically the foliage actor.

Perhaps rebuilding HLOD’s could fix this if it’s related to trees?
Not getting any errors on my end, tried deleting multiple instances of foliage an no errors on 5.2

Do you have debug symbols installed? It might give you more in-depth information on the crash. You should also have a log generated regarding the error.

Rosy · June 19, 2023, 6:25pm

I rebuilt HLOD, seems to have not done anything. This issue happens not only with trees but all foliage.

I’m currently downloading Debug Symbols to see if that provides any more insight

Rosy · June 19, 2023, 6:47pm

Alright! Here’s what Debug Symbols says:

Assertion failed: !IsValidChecked(ExistingActor) [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\ActorPartition\ActorPartitionSubsystem.cpp] [Line: 280]

UnrealEditor_Engine!FActorPartitionWorldPartition::GetActor() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\ActorPartition\ActorPartitionSubsystem.cpp:280]
UnrealEditor_Engine!UActorPartitionSubsystem::GetActor() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\ActorPartition\ActorPartitionSubsystem.cpp:440]
UnrealEditor_Engine!UActorPartitionSubsystem::GetActor() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\ActorPartition\ActorPartitionSubsystem.cpp:414]
UnrealEditor_Foliage!AInstancedFoliageActor::Get() [D:\build\++UE5\Sync\Engine\Source\Runtime\Foliage\Private\InstancedFoliage.cpp:3113]
UnrealEditor_FoliageEdit!SpawnFoliageInstance() [D:\build\++UE5\Sync\Engine\Source\Editor\FoliageEdit\Private\FoliageEdMode.cpp:1405]
UnrealEditor_FoliageEdit!FEdModeFoliage::AddInstancesImp() [D:\build\++UE5\Sync\Engine\Source\Editor\FoliageEdit\Private\FoliageEdMode.cpp:1535]
UnrealEditor_FoliageEdit!FEdModeFoliage::AddSingleInstanceForBrush() [D:\build\++UE5\Sync\Engine\Source\Editor\FoliageEdit\Private\FoliageEdMode.cpp:1559]
UnrealEditor_FoliageEdit!FEdModeFoliage::ApplyBrush() [D:\build\++UE5\Sync\Engine\Source\Editor\FoliageEdit\Private\FoliageEdMode.cpp:2675]
UnrealEditor_FoliageEdit!FEdModeFoliage::InputKey() [D:\build\++UE5\Sync\Engine\Source\Editor\FoliageEdit\Private\FoliageEdMode.cpp:3643]
UnrealEditor_UnrealEd!ULegacyEdModeWrapper::InputKey() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\Tools\LegacyEdMode.cpp:194]
UnrealEditor_UnrealEd!<lambda_98ab7ec1ce9ccabdd5a0c070cd0d3540>::operator()() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorModeManager.cpp:1313]
UnrealEditor_UnrealEd!FEditorModeTools::ForEachEdMode() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorModeManager.cpp:615]
UnrealEditor_UnrealEd!FEditorModeTools::InputKey() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorModeManager.cpp:1308]
UnrealEditor_UnrealEd!FEditorViewportClient::Internal_InputKey() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorViewportClient.cpp:2914]
UnrealEditor_UnrealEd!FLevelEditorViewportClient::InputKey() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\LevelEditorViewport.cpp:3047]
UnrealEditor_Engine!FSceneViewport::OnMouseButtonDown() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\Slate\SceneViewport.cpp:542]
UnrealEditor_Slate!SViewport::OnMouseButtonDown() [D:\build\++UE5\Sync\Engine\Source\Runtime\Slate\Private\Widgets\SViewport.cpp:242]
UnrealEditor_Slate!FEventRouter::Route<FReply,FEventRouter::FBubblePolicy,FPointerEvent,<lambda_310398f9f05d1d718df7855b2cc899ec> >() [D:\build\++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:420]
UnrealEditor_Slate!FSlateApplication::RoutePointerDownEvent() [D:\build\++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:4999]
UnrealEditor_Slate!FSlateApplication::ProcessMouseButtonDownEvent() [D:\build\++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:4947]
UnrealEditor_Slate!FSlateApplication::OnMouseDown() [D:\build\++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:4845]
UnrealEditor_ApplicationCore!FWindowsApplication::ProcessDeferredMessage() [D:\build\++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2227]
UnrealEditor_ApplicationCore!FWindowsApplication::DeferMessage() [D:\build\++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2726]
UnrealEditor_ApplicationCore!FWindowsApplication::ProcessMessage() [D:\build\++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:1895]
UnrealEditor_ApplicationCore!FWindowsApplication::AppWndProc() [D:\build\++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:925]
user32
user32
InkObj
atlthunk
user32
user32
UnrealEditor_ApplicationCore!FWindowsPlatformApplicationMisc::PumpMessages() [D:\build\++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsPlatformApplicationMisc.cpp:142]
UnrealEditor!FEngineLoop::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:5736]
UnrealEditor!GuardedMain() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:188]
UnrealEditor!GuardedMainWrapper() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:107]
UnrealEditor!LaunchWindowsStartup() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:244]
UnrealEditor!WinMain() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:284]
UnrealEditor!__scrt_common_main_seh() [D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
kernel32
ntdll

I’m trying to read this right now, but I’m not the best with cpp…

Rosy · June 19, 2023, 7:13pm

Removing all foliage from Data Groups fixes the issue, but is not ideal

3dRaven · June 19, 2023, 7:24pm

Rosy · June 19, 2023, 7:32pm

Well, I suppose that is the best solution known. Thanks for the help! I appreciate it greatly

system · July 19, 2023, 7:33pm

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