Lightmass Build Hanging at Specific Percentages

UE - Graphics Features - Sep 11, 2015

Lighting will build indefinitely in certain circumstances and can be verified in Swarm Agent that it will continue to process the maps even though the log shows it has completed. This is happening i ...

Copy-pasting (in the details panel) an array of structs containing multiline text not coming back entirely correctly

UE - Editor - UI Systems - Slate - Dec 20, 2016

This is the copy buffer (it contains multiline strings): ((SectionName_10_AD815C6B40E1AA91C8FB72B006CB648A="TeamScreen_Overview",TipHeader_8_0A891281438C7AD03199038A729ACC18="Heroes",TipBody_9_C20B ...

Incorrect mesh deformation when Max World Position Offset Displacement used

UE - Graphics Features - Nanite - Feb 12, 2025

When Vertex Animated Texture is used to animate a mesh with World Position Offset, often the Max World Position Offset Displacement Material setting must be increased or the Bounds Scale increased, ...

A 5.5 level that contains a Text3DComponent in a BP crashes the engine when opened in 5.6 (and up)

UE - Virtual Production - Sep 11, 2025

A 5.5 level that contains a Text3DComponent in a BP crashes the engine when opened in 5.6 (and up). The licensee has provided his analysis: Description: Level instance created in UE5.5 and re-saved ...

Collision Responses will reset to previous setting after changing the Preset Collision Profile

OLD - Anim - Mar 1, 2017

Collision Responses will reset to previous setting after changing the Preset Collision Profile. After the change is made and "Accept" is pressed, the Collision Responses will still have the old ch ...

Modules with Emitter Life functioning incorrectly

UE - Graphics Features - Jan 7, 2016

Setting the Emitter Time module with an emitter that is not set to loop will result in an incorrect render of the particles past the emitter duration. Emitter Duration set to 3 seconds:[Image Remov ...

StructUtils plugin's `FInstancedStruct` in a CPP-defined struct in a `TArray` on an actor component defined in CPP and implemented in BP. Populating the instanced struct in an actor BP's class defaults breaks serialization of the class defaults.

UE - AI - May 30, 2025

Context Instanced structs are great for holding simple data with the main advantage they have is a low memory overhead unlike instanced objects. Problem The problem is in StructUtils plugin's `FIns ...

'Moved' event pin doesn't trigger on the 'Input Touch' node correctly

UE - Editor - UI Systems - Apr 8, 2016

'Moved' event pin doesn't trigger on the 'Input Touch' node correctly Regression: This does not happen in 4.10.2. The 'Moved' pin triggers at all times when the mouse-button is held and the mouse i ...

Slider Values are not working inside of a blueprint

UE - Gameplay - Blueprint - May 7, 2015

Slider Values are not working inside of a blueprint in 4.8 Preview 1. User Description: Problem with the numeric float/int boxes in the editor in Blueprints, if for example open the TPS Template a ...

MetalRHI Asserts When Using "Profile GPU" With RHI-Thread/Parallel-Execution

UE - Graphics Features - Sep 14, 2016

When the RHI thread is enabled (with or without parallel-execution) for Metal it isn't currently possible to run "profilegpu" because the GPU timestamp emulation code isn't multi-thread safe and pro ...