Morph Targets fail to reset to zero

UE - Rendering - Architecture - RHI - Jan 6, 2026

"We have encountered a regression in UE 5.7 where Skeletal Mesh Morph Targets do not visually reset when all weights are set to 0.0. The mesh retains the deformation from the previous frame. This i ...

Navigation does not work in sub-levels

UE - AI - Jan 28, 2015

Navigation does not work in sub-levels. If the Nav Mesh Bounds Volume in a sub level is not touching a Nav Mesh Bounds Volume in the Persistent Level, it will not appear or function during Play. It ...

TargetArray nodes are reported as invalid if played in Standalone mode but not in PIE

UE - Gameplay - Blueprint - Feb 20, 2015

TargetArray nodes are reported as invalid if played in Standalone mode and the blueprints they are contained in are not rendered. Playing in PIE however works correctly and all blueprints are rende ...

Destruction mesh with Crumble Smallest and Impact near another will leave residual mesh visible

UE - Simulation - Physics - Destruction - Jan 28, 2015

When using a DM that has Crumble Smallest and Impact damage enabled there will be instances where the residual mesh before fracture is left behind. What appears to happen is there is a force large e ...

Fail to compile with Added AIController class

UE - Foundation - Core - Jan 14, 2015

User fails to compile code template after adding AIController code to project. Regression: Not a regression happens in 4.6.1 CL-2386410 Setting up Mono Building MyProjectEditor... Compiling game m ...

The AngularLimit visualizer isn't displayed as expected when adjusting the AngularRotationOffset

UE - Simulation - Physics - Dec 9, 2016

The AngularLimit visualizer isn't displayed as expected when adjusting the AngularRotationOffset. You can manually rotate the PhysicsConstraint and it will rotate the AngularLimit visualizer, howe ...

Translucent light grid injection behavior

UE - Graphics Features - Nov 15, 2024

Light injection into the Translucent Light Grid voxels does not use the correct location for clipping or attenuation. Both of these points are outside the voxel that is being updated. Light attenua ...

Compiler error after changing the class in a Spawn Actor from Class node, undoing with Ctrl + Z, refreshing the node, and reconnecting exposed variables

UE - Gameplay - Blueprint - May 26, 2015

Compiler error after changing the class in a Spawn Actor from Class node, undoing with Ctrl + Z, refreshing the node, and reconnecting exposed variables. "Error Internal compiler error inside Creat ...

Drag and Drop fails in Standalone and Packaged builds when WidgetComponent’s Widget is set at runtime

UE - Editor - UI Systems - Dec 4, 2025

When a UWidgetComponent has its widget assigned dynamically at runtime using CreateWidget and SetWidget, drag & drop operations fail in Standalone Game and packaged/game builds, while working correc ...

Attempting to use the GameplayTags module in a binary code project will result in build failures in Visual Studio.

UE - Foundation - Core - Mar 27, 2015

Using the GameplayTags module in a code project created with the binary version of the Engine results in a build failure in Visual Studio. The following error is shown: 1> D:/Epic Games/4.7/Engine ...