Crash when Undo after deleting a Material Layer of a Material Instance.

UE - Rendering - Architecture - Materials - Apr 2, 2025

In Unreal Engine version 5.5.4, the Editor crashes when performing Undo after deleting a Material Layer of a Material Instance ...

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 ...

CppCompileWarningSettings.NonInlinedGenCppWarningLevel messages should contain Warning\Error

UE - Core - Cpp Tools - UnrealBuildTool - Oct 8, 2025

The messages emitted when CppCompileWarningSettings.NonInlinedGenCppWarningLevel is set to Warning\Error should contain the literal so the tools pick them up and react accordingly. From the EPS c ...

Packaging for DLC with plugin multiple times causes failure due to file path length

When the DLC is being built for a project and stored in a plugin, the result is normaly until the DLC is packaged multiple times. This leads to the file path becoming more and more nested each time. ...

Add Submix Effect Blueprint Does Not Have Any Effect

UE - Audio - Dec 11, 2020

Adding a second effect to the Submix Effect Chain on a Submix works as expected, but when trying to add a Submix Effect via Blueprint, there is no effect.  This also applies to "Add Master Submix Ef ...

A chaos vehicle that moves at very high speeds with CCD enabled on the vehicle sometimes has a collision response that is abnormal where the vehicle loses a significant amount of speed when colliding with dynamic objects configured as One Way Interaction

UE - Runtime - Character - Dec 16, 2025

Context: Continuous Collision Detection (CCD) is being used on a Chaos Vehicle to avoid tunneling issues with certain surfaces as it prevents any missed collisions between fast moving particles and ...

Cumulative Patching does not work with Pak signing

UE - Core - Systems - Feb 20, 2024

Cumulative patching is implemented by copying the generated pak files during staging of the base and each patch to the Releases directory. When creating a patch, all of the pak files from the releas ...

Crash when a StateTree-related Parameter is of a type that includes two nested arrays with the same name (due to FPropertyChangedEvent::ArrayIndicesPerObject using array names to map to their changed indices)

UE - Framework - Dec 19, 2025

This issue was reported in the context of adding and setting parameters on StateTrees, Tasks and related assets, but its root cause lies in the structure FPropertyChangedEvent and can possibly affec ...

SceneTexture:WorldNormal causes decal to ignore Emissive Color

UE - Rendering - Architecture - Materials - Mar 11, 2022

SceneTexture:WorldNormal causes decal to ignore Emissive Color.  ...

Event Dispatcher implementation called several times (number of bound refs increases every compile)

UE - Gameplay - Jun 26, 2018

The number of calls to the Event Dispatcher increase each time the blueprint actor containing the reference is compiled. This issue was not present in 4.18.3 (CL-3832480) but is in 4.19.2 (CL-403378 ...