Compile on load crashes for classes within an abstract class

UE - Gameplay - Blueprint Compiler - Feb 20, 2021

When compiling on load in -game, a blueprint class that inherits from a native class that is marked within and the class that it is within is abstract, a crash will occur when FBlueprintCompilationM ...

Incorrect volume bounds check in FTranslucentLightInjectionCollector::AddLightForInjection

UE - Graphics Features - Apr 8, 2025

The 'VolumeBounds' array in FTranslucentLightInjectionCollector::AddLightForInjection is accessed as a pointer instead of with 'VolumeCascadeIndex' and thus fails bounds checks for the outer volume. ...

Setting Slate.ShowBatching to 1 makes the entire screen green unexpectedly

UE - Editor - UI Systems - Slate - Jun 19, 2025

This issue may have occurred due to a refactoring of the related functionality during the engine update from version 5.4 to 5.5. The main reason is that the randomization of BatchColor doesn't work ...

Differences in Post Process FX between Minimized and Maximized Viewport

UE - Graphics Features - Apr 19, 2016

When scaling the viewport window using the Maximize/Minimize viewport option, the post processing effects applied to the screen do not scale properly. This issue seemed trivial at first, as the use ...

Sometimes CharacterMovement stops at very low steps (quite lower than Max Step Height).

UE - Gameplay - Player Movement - Jul 11, 2016

Sometimes CharacterMovement stops at very low steps (quite lower than Max Step Height). Capsule radius of Character is 50cm, Max Step Height is 45cm, step heights is around 10~30cm, MaxWalkSpeed is ...

Random Number Generated in Constructor Returning Different Value on Begin Play

UE - Gameplay - Jan 13, 2016

When generating a random number using FMath::RandHelper() in the constructor of an actor, attempting to print that same number on BeginPlay returns a different value than the constructor. However, ...

Media Texture Not Displaying When Launched to Android Device

UE - Rendering Architecture - Materials - Dec 17, 2015

UPDATE: 12/23/2015 This appears to be occurring on packaged projects for Win64 as well. ====================================================================== When attempting to launch a level t ...

SunTemple scene does not update properly on iPhone 6S

UE - Platform - Mobile - Jul 18, 2017

On the 6S, the SunTemple scene is almost unresponsive. As the player uses the thumbsticks, the lightmaps from the windows rotate to mach the player's movement; but they are the only thing. This doe ...

Certain combined Linear/Angular movements cause Client to freeze for several seconds

UE - Simulation - Physics - May 24, 2019

When using Replicated Movement, certain combined linear/angular movements cause the client to freeze for several seconds and then catch up to the server. This is a regression from 4.21.2 (CL-4753647 ...

RemoveAxisMapping() removes axis mappings of the same key regardless of Scale value

UE - Gameplay - Jun 26, 2019

When you remove an axis mapping using a specific key it will remove all mappings even if they have separate scales. The user found a fix that I verified that worked. In "InputSettings.cpp", which i ...