Assert failed at landscape height field collision component serialization

anonymous_user_357b6e5a · April 6, 2016, 11:50am

Hi. I have an assertion failure at Play in PIE (Debug Editor, build from source) from any landscape height field collision component.

There is a callstack:

UE4Editor-CoreUObject-Win64-Debug.dll!FUObjectAnnotationSparseSearchable::AddAnnotation(const UObjectBase * Object, FUniqueObjectGuid Annotation) Line 303	C++

UE4Editor-CoreUObject-Win64-Debug.dll!FLazyObjectPtr::PossiblySerializeObjectGuid(UObject * Object, FArchive & Ar) Line 142	C++

UE4Editor-CoreUObject-Win64-Debug.dll!UObject::Serialize(FArchive & Ar) Line 958	C++

UE4Editor-Engine-Win64-Debug.dll!UActorComponent::Serialize(FArchive & Ar) Line 1627	C++

UE4Editor-Engine-Win64-Debug.dll!USceneComponent::Serialize(FArchive & Ar) Line 1809	C++

UE4Editor-Engine-Win64-Debug.dll!UPrimitiveComponent::Serialize(FArchive & Ar) Line 586	C++

UE4Editor-Landscape-Win64-Debug.dll!ULandscapeHeightfieldCollisionComponent::Serialize(FArchive & Ar) Line 1247	C++

UE4Editor-CoreUObject-Win64-Debug.dll!StaticDuplicateObjectEx(FObjectDuplicationParameters & Parameters) Line 1823	C++

UE4Editor-CoreUObject-Win64-Debug.dll!StaticDuplicateObject(const UObject * SourceObject, UObject * DestOuter, const FName DestName, EObjectFlags FlagMask, UClass * DestClass, EDuplicateForPie DuplicateForPIE, EInternalObjectFlags InternalFlagsMask) Line 1716	C++

UE4Editor-UnrealEd-Win64-Debug.dll!UEditorEngine::CreatePIEWorldByDuplication(FWorldContext & WorldContext, UWorld * InWorld, FString & PlayWorldMapName) Line 3534	C++

UE4Editor-Engine-Win64-Debug.dll!UGameInstance::InitializePIE(bool bAnyBlueprintErrors, int PIEInstance, bool bRunAsDedicated) Line 158	C++

UE4Editor-UnrealEd-Win64-Debug.dll!UEditorEngine::CreatePIEGameInstance(int PIEInstance, bool bInSimulateInEditor, bool bAnyBlueprintErrors, bool bStartInSpectatorMode, bool bRunAsDedicated, float PIEStartTime) Line 2730	C++

UE4Editor-UnrealEd-Win64-Debug.dll!UEditorEngine::PlayInEditor(UWorld * InWorld, bool bInSimulateInEditor) Line 2324	C++

UE4Editor-UnrealEd-Win64-Debug.dll!UEditorEngine::StartQueuedPlayMapRequest() Line 1100	C++

UE4Editor-UnrealEd-Win64-Debug.dll!UEditorEngine::Tick(float DeltaSeconds, bool bIdleMode) Line 1251	C++

UE4Editor-UnrealEd-Win64-Debug.dll!UUnrealEdEngine::Tick(float DeltaSeconds, bool bIdleMode) Line 370	C++

UE4Editor-Win64-Debug.exe!FEngineLoop::Tick() Line 2643	C++

...
TAnnotation ExistingAnnotation = this->GetAnnotation(Object);

if (!Annotation.IsDefault())

{
	int32 NumExistingRemoved = InverseAnnotationMap.Remove(ExistingAnnotation);
	**checkSlow(NumExistingRemoved == 0);**
}



Land was created in 4.11


> Assertion failed: NumExistingRemoved
> == 0 [File:d:\projects\UnrealEngine\UnrealEngine.git\Engine\Source\Runtime\CoreUObject\Public\UObject\UObjectAnnotation.h]
> [Line: 303] 
> 
> UE4Editor-Win64-Debug.exe has
> triggered a breakpoint.

where NumExistingRemoved  == 1 instead 0

ziga.osolin · April 6, 2016, 5:20pm

I have the same issue in debug mode in PIE, but for other actors in some legacy maps. They work in non-debug mode though … (probably checkSlow is compiled out there).

anonymous_user_6e7b421a · April 6, 2016, 8:32pm

Hey guys,

Could either of you provide me with some simple steps to reproduce this in a either the binary/source build of a new blank project?

Thank you,

anonymous_user_357b6e5a · April 6, 2016, 10:34pm

There is an example project (source build, basic c++ blank project):

https://drive.google.com/open?id=0B6VhapqQv3c4bkhGMG9LXzFnT1k

Generate project files (source build, 4.11)
Build configuration Debug Editor.
Run debug editor with my project
Open map Landscape_crash_test
Play.
Take assertion failure.

MSE_Taliesin · April 7, 2016, 7:08pm

We’re experiencing the exact same issue with all of our maps after upgrading to 4.11. They all worked fine in 4.10 and run fine in Development builds, but this is preventing us from running any of our maps in debug.

MSE_Taliesin · April 7, 2016, 10:09pm

A bit more info: I deleted the landscape just so I could run the game and debug something … and this time I got the same crash, but on a static mesh. So it’s not strictly limited to landscapes.

MSE_Taliesin · April 7, 2016, 10:22pm

Here’s a shot of the call stack & watch window when it crashes on the static mesh component. Let me know if log files for this would also be helpful.

chrcy · April 15, 2016, 2:03am

Any update on this, will it be fixed 4.11.2 ?

anonymous_user_357b6e5a · April 21, 2016, 10:42am

Any news about this issue? Is it enough to be noted as bug?

anonymous_user_6e7b421a · April 21, 2016, 8:29pm

@ v.s. I followed your instructions and did not the get crash to occur. I will say I toggled a breakpoint error that occurred when I ran in debug mode while launching the project. However, I was able to open and play in editor without getting a crash.

Could anyone experiencing this issue provide me with a their official crashlogs for this project so I can investigate this further?

Thank you,

anonymous_user_357b6e5a · April 21, 2016, 8:38pm

This problem is actual for debug mode only. But it is present in development build too. But wihout triggering of the assertion. We can not normally work on in the debug editor, and we can not run any map in PIE with the landscape without triggering this assertion. There is a new situation which was not until 4.11. Is this a normal behavior?

anonymous_user_357b6e5a · April 22, 2016, 6:39am

There is a problem with a duplication of ALandscapeProxy class inside PIE. Special handling is required to serialize this class because Guid copies detected at runtime StaticDuplicateObjectEx for LandscapeComponents and CollisionComponents. I think that this case should be considered.

anonymous_user_b5e690271 · April 26, 2016, 9:32am

Same issue here. Happens on a Brush component, but only in a debug build when PIE is started.

anonymous_user_6e7b421a · April 26, 2016, 4:55pm

Could you provide me with some simple steps, your crash logs, and an explanation of what you are doing when the crash occurred?

I am trying to get this issue to appear on my end so I can report the bug, but so far I have been given a project where the issue is not occurring. If I can get your crash logs, and there is enough information, I can enter a report using the crash reporter information.

Thank you,

anonymous_user_357b6e5a · April 26, 2016, 5:04pm

There is an assertion failure but not a classic crash as a wrong pointer, etc. Assertion occurs ONLY in the Debug Build of the editor. This problem does not come out itself in the form of the classic crash in Development Build, but points to the existing problem of copying objects.

anonymous_user_357b6e5a · April 27, 2016, 1:38pm

Such a case was considered like this. What this case is different from the specified?

anonymous_user_6e7b421a · April 27, 2016, 2:15pm

The reason that bug was entered was because the technician was able to get a repro case from the instructions you provided. If I cannot get the issue to reproduce on my end, there is not enough information to generate the bug report. The bug that was entered also dealt with a crash, and did not address the assert specifically.

anonymous_user_357b6e5a · April 27, 2016, 2:32pm

I truly expresses the cause of this incident, if I am correct description from crash to assertion failure, it will be right?

I did a correction of description of reproduction steps. There is an assertion failure only.

jolt · April 30, 2016, 7:16am

This issue is easy to reproduce, exactly as OP reported:

checkout 4.11.2
build “Debug Editor” Win64
start debugging
create new blank project without starter content
in the editor create a landscape
then Play
crash (assert → checkSlow(NumExistingRemoved == 0))

So either the DBC check is not valid, or there is some other underlying issue resulting in NumExistingRemoved not being zero. I’ve not had the time to investigate the UE code further to understand the intention of this check. So our work around has been to simply comment out the checkSlow(NumExistingRemoved == 0).

Our callstack is same as OP e.g.:

UE4Editor-CoreUObject-Win64-Debug.dll!FUObjectAnnotationSparseSearchable<FUniqueObjectGuid,1>::AddAnnotation(const UObjectBase * Object, FUniqueObjectGuid Annotation) Line 303	C++
.............. etc.

i.e. check fails at line Engine\Source\Runtime\CoreUObject\Public\UObject\UObjectAnnotation.h 303 marked ** below.

void AddAnnotation(const UObjectBase *Object,TAnnotation Annotation)
{
...
		TAnnotation ExistingAnnotation = this->GetAnnotation(Object);
		if (!Annotation.IsDefault())
		{
			int32 NumExistingRemoved = InverseAnnotationMap.Remove(ExistingAnnotation);
			checkSlow(NumExistingRemoved == 0);**
		}
		...
}

Where:
-		NumExistingRemoved	1	int
-		Object	0x0000013de0021600 (Name=0x0000013d9758c020 "LandscapeHeightfieldCollisionComponent"_63)	const UObjectBase *
+		[ULandscapeHeightfieldCollisionComponent]

Also see log attached link text

anonymous_user_41845f4a · May 10, 2016, 9:12pm

Hello everyone,

Thank you for the reproduction steps. I was able to reproduce the crash in a version of 4.11.2 that I downloaded from Github but did not get the same results on our latest internal build. I’ll be testing on 4.12 shortly to see if it occurs there. In the meantime, would you be able to download the latest Promoted build from Github and see if you’re experiencing the crash on that branch?