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 ...

The 'Set Constrained Components' node doesn't set the physics constraint components correctly if used in the Construction Script

UE - Simulation - Physics - Jan 20, 2015

The 'Set Constrained Components' node doesn't set the physics constraint components correctly if used in the Construction Script. ...

The Sorting Issue Between Height Fog and Transparent Objects

UE - Graphics Features - Aug 21, 2024

When a LocalFogVolume is used with ExponentialHeightFog, it does not correctly fog translucent objects. ExponentialHeightFog and Volumetric Fog from a LocalFogVolume both correctly occlude transluc ...

Widget "Listen For Input Action" executes on unexpected input event

UE - Editor - UI Systems - Feb 19, 2020

Listen For Input Action firing erroneously. Confirmed in 4.26 MAIN @ CL 11536993 ...

Destructible attached with a Physics Constraint have inconsistent physics

UE - Simulation - Physics - Destruction - Jul 26, 2016

Destructible attached with a Physics Constraint have inconsistent physics compared to a standard Static Mesh. This is also sometimes prevalent with Destructibles that aren't attached with a Physics ...

Incorrect derivative ops detection when Add node is used with Nanite Pass Switch node in material graph

UE - Graphics Features - Mar 11, 2025

Plugging an Add node which adds a constant value into a Nanite Pass switch node results in derivative ops to be detected where there should be none (which show up as red in the No Derivative Ops deb ...

Crash, Couldn t find Shader FHitProxyVS for Material Resource M_Glass

UE - Graphics Features - Aug 18, 2014

Changing the properties of M_Glass and M_Metal_Copper to two sided via the property matrix crashes the editor to desktop. (Note: M_Glass with ANY of the M_Metal Materials except M_Metal_Chrome will ...

Crash when using StaticDuplicateObject with mismathced Source and Destination class types

UE - Foundation - Jun 19, 2025

Starting in Unreal Engine 5.4, StaticDuplicateObject internally switched to using Unversioned Property Serialization (UPS) for performance reasons. However, UPS assumes the source and destination ob ...

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 ...