Crash in UDataTable::RemoveRow(FName RowName)

UE - CoreTech - Jun 13, 2025

This is a regression, the crash seem to have been introduced by CL 40129784 on ue5-main and persists in latest. Function UDataTable::RemoveRow(FName RowName) uses macro DATATABLE_CHANGE_SCOPE_SINGL ...

FileSystemDerivedDataBackend may output a corrupted access log

UE - Foundation - Core - Derived Data - May 20, 2021

This problem is caused by the AccessLogWriter has not been flushed at the termination. The following workaround flushes the Writer.class FFileSystemDerivedDataBackend : public FDerivedDataBackendInt ...

Hot reload can prevent code components from being accessible in blueprints

UE - Foundation - Cpp Tools - Hot Reload - Sep 29, 2017

When a class is edited / hot reload preformed, code based components are sometimes removed from the MyBlueprint > Variables section and cannot be dragged from the Components tab into the graph with ...

GAS PlayMontageAndWait: Server applies root motion with wrong scale at last montage tick

UE - Gameplay - Gameplay Ability System - Apr 3, 2024

User reported: when playing an AnimMontage via GameplayAbility with the PlayMontageAndWait ability task that has a custom value for AnimRootMotionTranslationScale, (dedicated) servers can apply an i ...

Damping is handled differently at lower frame rates

UE - Gameplay - Aug 3, 2016

Damping is handled differently at lower frame rates. Slight changes in damping at lower FPS (25) drastically effects objects and isn't applied in the same way as at higher FPS (60) User Description ...

Creating a float variable named lifespan in an Actor Blueprint and setting its default value will override the life span of the parent class

UE - Gameplay - Blueprint - Dec 19, 2016

Creating a float variable named lifespan in an Actor Blueprint and setting a default value for it will override the parent class' life span setting. I was unable to find any variable in the Actor cl ...

OnComponentWake Event does not trigger when the physical body is awoken by a Force

UE - Simulation - Physics - Feb 27, 2025

OnComponentWake Event does not trigger when the physical body is awoken by a Force. The steps described on Steps To Reproduce is enough to replicate this behavior. The OnComponentWake event is only ...

GeneratePsyms fails with installed builds due to missing dymp_syms tool and incorrect path space handling

UE - Platform - Apple - Nov 14, 2024

Uncovered while testing [Link Removed] ...

In Standalone mode, when reading world partition actor descriptors for BP actors, "bIsSpatiallyLoaded" receives its value from the native base class instead of the BP class, so BP actors are loaded/unloaded based on the wrong condition.

UE - World Creation - Worldbuilding Tools - World Partition - Oct 15, 2024

Consider an actor defined in C++ with "bIsSpatiallyLoaded" set to true (the default), and a derived blueprint that overrides "bIsSpatiallyLoaded" to false. Now consider an actor instance of that blu ...

Using Delay with Tick when Paused doesn't work

UE - Gameplay - Blueprint - May 28, 2015

Using a delay node in an event graph of actor using tick when paused will not work. It pauses the delay node. ...