World position offset (WPO) and nanite enabled causes shadow of complex static mesh actor to be deformed at a specific distance

UE - Graphics Features - Nanite - Dec 19, 2024

Context / Problem: Complex static mesh actors with nanite enabled and Evaluate World Position Offset (WPO) enabled works together except for a specific distance where the shadow is deformed and sort ...

BlueprintNativeEvent functions break on hot reload

UE - Gameplay - Blueprint - Mar 7, 2015

A blueprint that uses a node for a BlueprintNativeEvent function breaks on hot reload. Blueprint cannot be saved or compiled. Compile error states: Error This blueprint (self) is not a HOTRELOADED ...

Crash when setting Project to only use Windows and DX11 with texture compression as BC7

UE - Graphics Features - Jan 11, 2016

When user sets their texture compression to BC7 while the project settings are set for Platform to only be Windows and use only DX11 this will cause any textures with this set to cause a crash when ...

Setting Pressed Sound for Widget Style Doesn't Set the Value

UE - Editor - UI Systems - Nov 6, 2015

Attempting to set the Pressed Sound for Widget Style dynamically never actually sets the sound. When you click the button, you get no pressed sound. However, when setting the Pressed Sound through t ...

Cannot pass a Dictionary through a Replicated Function

UE - Networking - Aug 23, 2018

When passing dictionary (map) variables through replicated (to server) functions, the value will not print out on the client. In 4.19.2 (CL-4033788) this caused a crash but in 4.20.2 (CL-4302132) an ...

tvOS crash on startup with Shared Material Shader Code enabled

UE - Platform - Mobile - Jul 9, 2019

Enabling Shared Material Shader Code will cause a crash on tvOS From user: "We originally enabled Share Material Shader Code long before trying a tvOS build, making this crash tricky to debug. W ...

Child actor passes a string to it's parent's overloaded constructor the incorrect string is received

UE - Gameplay - Sep 24, 2019

When a child actor passes a string to it's parent's overloaded constructor using an overridden function that returns a string it won't receive the correct string. I have verified that the correct fu ...

Masked TwoSided material causing lumen direct lighting to leak through walls

UE - Graphics Features - Lumen - Apr 23, 2024

It appears that LumenScene's Hardware Ray Tracing is causing light leaking into a sealed room (which should be perfectly black). This bug does not appear to happen on AMD GPUs. ...

High Virtual Texture Sample/Lookup Cost when using a Virtual Texture in a Material Layer Blend

UE - Rendering Architecture - Materials - Mar 14, 2025

Some Material Attribute blends in Material Layer Blends can cause Virtual Texture samples to be duplicated in HLSL. This can be avoided by sampling the Virtual Texture in the Parent Material, and pa ...

Packed level actors and Level instances are sometimes not included in HLOD build on a World Partition Level

UE - World Creation - Worldbuilding Tools - HLOD - Mar 14, 2025

Context World Partition - Hierarchical Level of Detail (HLOD) system uses custom HLOD Layers to organize large amounts of Static Mesh Actors and generate a single proxy mesh and Material. Problem T ...