Unable to use TWeakObjectPtrs for the optional Old value for a repnotify function

UE - Foundation - Cpp Tools - UnrealHeaderTool - Oct 8, 2018

A user has reported that Unreal Header Tool fails to parse a rep notify function properly when the optional parameter for the Old value is populated with a TWeakObjectPointer. Example of errors:Sev ...

Packaged ThirdPerson template with "start in vr" enabled packaged and launched with "-nohmd" crashes

UE - Platform - XR - Mar 31, 2021

The callstack is not XR-specific, it's just the engine trying to secure the audio device on startup, windows failing to return one, and the app not being able to continue safely. The crash does not ...

Invalid GUIDs on new material instance parameters cause overrides to break on base param rename

UE - Rendering - Architecture - Materials - Sep 3, 2025

When a parameter value is assigned on a newly created material instance (constant or dynamic) using Set***ParameterValueInternal, the parameter’s ExpressionGUID is left invalid (0,0,0,0). Parameter ...

Undo after disconnecting a target pin will cause a series of internal compile errors

UE - Gameplay - Blueprint - Mar 15, 2016

Undo after disconnecting a target pin will cause a series of internal compile errors User Description: I've run into what I think is a bug when attempting to compile a blueprint after mistakenly b ...

[AI] Navmesh shows in editor but does not get loaded in PIE

UE - AI - Navigation - May 13, 2024

When using static or dynamic modifiers only navmesh, there are times that the navmesh will build and display correctly in editor, but it does not get properly loaded at runtime (PIE/SIE). The Recast ...

[CrashReport] UE4Editor_Engine!USceneComponent::DestroyComponent() [scenecomponent.cpp:847]

UE - Gameplay - Components - Dec 1, 2017

[Edit]: This should no longer be a crash as of 4.19.2 - we should only get ensure() reports with this callstack. ===== This is a common crash coming out of 4.18. Users have not provided any descript ...

Unable to launch project from Visual Studio using installed engine build

UE - Foundation - Build - Farm - Feb 23, 2017

When a code project's engine association is switched to a local binary version of a source engine, the project will fail to open from within Visual Studio. Error message says that UE4Editor-Project ...

[MetaSounds] - Trigger on Threshold node Crashes editor on play when using literal value for threshold

UE - Audio - MetaSounds - Mar 15, 2022

Editor crashes when Trigger on Threshold node is hooked up in a Metasound graph and played using a threshold value defined on the node. If you use an Input node for the Threshold value, the crash do ...

Crash w. 'Serialized Class LinkerPlaceholderExportObject for a property of BlueprintGeneratedClass'

UE - Gameplay - Blueprint - Sep 25, 2017

I was attempting to repro [Link Removed]. I created a new Actor BP, placed it in the level, added a ref to it to the level BP (instead of the projectile approach in the repro), and tried to save my ...

Cannot access private member MarkPropertyDirtyFromRepIndex error when building a nativized blueprint with a replicated property

UE - Networking - May 14, 2020

The following error occurs when building a project that has a replicated variable with the replication condition set to Skip Owner inside a nativized blueprint.UATHelper: Packaging (Windows (64-bit) ...