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 ...

Line trace fails to detect Destructible Mesh

UE - Simulation - Physics - Destruction - Jun 15, 2015

When using a line trace in the construction script so that objects can return a value destructible meshes will not return a hit. This does not affect use in game with PIE or Standalone game, but if ...

Soft References resolved at Runtime result in References to Persistent Assets

UE - Gameplay - Aug 23, 2018

It is believed that soft references resolved during runtime, point to the edit time instances of actors instead of the runtime instances. This issue does not reproduce when it is called from an Inp ...

Nativizing Blueprint fails when struct is not initialized properly

UE - Gameplay - Aug 27, 2018

The PreferredNavData member of NavAgentProperties isn't properly initialized. It is using some constructor that doesn't seem to be valid. This is a regression from 4.19.2 (CL-4033788) as this same s ...

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 ...

Behavior of reparenting Component on UE5 is different from UE4

UE - Gameplay - Blueprint Editor - Mar 29, 2022

In UE4, Reparenting the Child Component did not update it on the screen, but the Relative Transform was updated. However, UE5 now retains Relative Transform, so there are on-screen updates. This is ...

Virtual Heightfield Mesh crash using released Vertex Factory

UE - Rendering Architecture - Jul 25, 2023

When using VirtualHeightfieldMesh we see intermittent crashes in FDepthPassMeshProcessor::TryAddMeshBatch(). This can happen when FVirtualTextureProducerCollection::CallPendingCallbacks() is called ...