A build may fail in Visual Studio if a space is added after the # in an include pre-processor instruction to allow a struct in one header file to reference a struct in the other

UE - Foundation - Core - Sep 23, 2016

A project building in Visual Studio will sometimes fail with the error Unrecognized type 'FBar' - type must be a UCLASS, USTRUCT or UENUM. This can occur in situations where one struct was reference ...

Hot Reload crash on PIE with custom AIController and Perception Component

UE - AI - Sep 29, 2015

If a pawn in the level is using a custom AI Controller that sets the AIPerceptionComponent in code, the editor will crash on PIE after a hot reload. CrashReporter: [Link Removed] ...

StartCameraFade() breaks on mobile projects after editor is closed/reopened

UE - Platform - Mobile - Oct 6, 2015

If a project that is set to Mobile/Tablet and Scalable 3D or 2D uses StartCameraFade() to produce a fade in effect, the effect will not play in PIE if the editor is closed/reopened. ...

Instanced object in an array property of an actor component is invalidated and marked for garbage collection on undo

UE - Gameplay - Jun 4, 2024

If an actor component contains a TArray of instanced objects, some of those object instances can get incorrectly invalidated and marked for garbage collection in certain situations, possibly resulti ...

Values are not copied for a EnumArray that is part of an exposed Struct Variable

UE - Gameplay - Blueprint - Jun 21, 2016

Values are not copied for a EnumArray that is part of an exposed Struct Variable; when copying from the Details panel to a copy of the same actor. User Description: If you make an array of custom ...

Crash occurs if the Recast Navmesh is set to Dynamic and the BehaviorTree runs a 'Does Path Exist' decorator

UE - AI - Jun 16, 2015

Crash occurs if the Recast Navmesh is set to Dynamic and the BehaviorTree runs a 'Does Path Exist' decorator. Crashreporter info: [Link Removed] ...

[CrashReport] GPU Hang on Linux - /usr/lib/nvidia-381/libGLX_nvidia.so.0

UE - Platform - Linux - Aug 16, 2017

This is a trending GPU hang crash on Linux in 4.16 and 4.17. It is similar to [Link Removed] (nvidia-375) ...

Mesh painting on staticmesh doesn't always apply Colors to All LODs

UE - Editor - Content Pipeline - Asset Build - Apr 18, 2022

See the video [Link Removed] ...

Trace complex for assets simulating physics does not show accurate collision

UE - Gameplay - Apr 27, 2015

When using Trace Complex in a LineTraceByChannel node does not give accurate results when object is simulating physics and scaled. The scaled root mesh in the BP will only register its collision rat ...

Possible bug with GAOGlobalDistanceFieldCacheMostlyStaticSeparately

UE - Rendering - Graphics Features - Jun 2, 2025

The Global Distance Field can constantly update, even when the camera is stationary, in large World Partition maps. This bug requires a large amount of the World Partition map to be loaded to reprod ...