Duplicating a blueprint that implements an interface and then removing that interface will cause compile errors that don't occur if the interface was removed from the original BP

UE - Gameplay - Blueprint Editor - Aug 1, 2020

See steps to reproduce. Looks like the fixup when saying Yes to "Would you like to transfer the interface functions to be part of your blueprint" doesn't work correctly on the duplicated BP. Inter ...

GAMEPLAYATTRIBUTE_REPNOTIFY does not properly propagate OldValue

UE - Gameplay - Dec 10, 2021

Associated UDN [Link Removed] We've been having some issues with the replication of attributes. Namely we have an OnRep_ function for an attribute that receives FGameplayAttributeData& OldValue a ...

TBaseBlendedCurve::ConvertToAdditive adds a curve track to an additive when the curve only exists in the base pose

UE - Anim - Runtime - May 29, 2023

When we create curves on additive animations, we are creating a curve based on whether the curve exists in either the base or additive pose.  This wouldn't be the expected behaviour for a user when ...

GameFeature Plugins do not chunk as expected when using PrimaryAssetLabels

UE - Gameplay - Sep 23, 2024

There is some unexpected behaviour around GameFeature Plugins (GFPs) when packaging with chunking enabled most noticeable when using PrimaryAssetLabels (PALs). Firstly, PrimaryAssetLabels do not ap ...

Property won't be force synced when re-enabling replication.

UE - Networking - Mar 21, 2017

It seems like if replication is re-enabled for a given property, its state should be force synced (depending on replication conditions). Otherwise, the state will remain "out of sync" for an indeter ...

[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 ...

Adding a widget to a grid panel inside the grid panel tick can cause an out-of-bounds error

UE - Editor - UI Systems - Slate - Jan 25, 2021

This is caused by adding an item to a grid panel inside the grid panel iteration loop. The same operation to canvas panel goes well without any errors. The difference is that the array iteration in ...

Replicated components spawned by CreateComponentOnInstance are broken by object reuse

UE - Gameplay - Apr 5, 2023

When the gameplay framework component manager creates components as part of CreateComponentOnInstance, it passes in the requested class name as the literal name of the component instead of using the ...

MoviePlayer loading screen with FLoadingScreenAttributes::bAllowEngineTick results in high DeltaSeconds tick post-playback

UE - Framework - Feb 16, 2024

IGameMoviePlayer playback of a movie during loading screen lets you set bAllowEngineTick  = true as a parameter. This will make FDefaultGameMoviePlayer manually tick the engine: if (GEngine && bAll ...

Generated world partition maps cause AssetManager warnings

UE - Foundation - Data Pipeline - Cooker - May 29, 2024

When cooking world partition maps, it automatically writes out several maps in a "Generated" folder below the location of the map in the editor. In the repro above, this will create maps such as /Ga ...