Mouse functionality breaks on Linux when game is full screen on multi-monitor setup

UE - Platform - Linux - Mar 1, 2016

When the game window is maximized on any monitor other than the left most monitor, the mouse will not interact with the game window. ...

Destructible Mesh spawned before static mesh with World or Asset support is not supported

UE - Simulation - Physics - Destruction - Apr 27, 2015

When using World Support or Asset Defined Support on a Destructible mesh that is spawned in, if the static world geometry is spawned in after the DM it will not be supported. However, if the static ...

Duplicated PCG Component instance resets overridden parameters to default

UE - World Creation - Procedural Tools - PCG Component - Jun 4, 2025

Context: Similar to parameters in the Material editor, PCG Graph Parameters are user created overridable values and can help create customizable graphs for a variety of situations. Problem: The l ...

Toggling a Spline component from an open/closed loop through bp's isn't reflected

Tools - Jan 19, 2015

Toggling a Spline component from an open/closed loop through bp's isn't reflected ...

Some post-processing passes sample outside of the viewport when using scene capture components

UE - Graphics Features - Nov 29, 2023

It looks like the SSAO shader does not clamp its sample space to the half view size for the two inputs "Ambient Occlusion" and "AmbientOcclusionSetup", leading to invalid data entering the edge of f ...

Niagara mesh particles have incorrect normals when scaled

UE - Niagara - Apr 27, 2020

Niagara mesh particle normals do not match those of static mesh actors. ...

bIgnoreAllPressedKeysUntilRelease behaves differently for triggers in EnhancedInputAction and triggers in InputMappingContext

UE - Gameplay - Input - Aug 10, 2023

For actions that are triggered on the Input mapping context, simply adding or removing an InputMappingContext with no related key override with the bIgnoreAllPressedKeysUntilRelease option will caus ...

Blueprint - Crash when a function takes an event as a parameter

UE - Gameplay - Blueprint - Oct 10, 2016

Looks like maybe we aren't replacing the source delegate function (SignatureFunction) reference on the UDelegateProperty after recompiling the class - the function's owner name has the TRASHCLASS pr ...

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 ...

BP timelines: when converting internal curve to external, the external curve isn't used until BP is recompiled

UE - Framework - Blueprint Editor - Aug 28, 2023

Blueprint timelines: when converting an internal curve to an external curve asset, the curve asset's data isn't used until the blueprint is recompiled. This is confusing as there is no indication th ...