[Mobile/Forward Rendering] PlanarReflection does not work when the reflection plane faces certain directions

UE - Platform - Mobile - Sep 24, 2025

Note: This repros on 4.27 and all 5.x versions. When using the mobile renderer and/or forward shading, Planar Reflection will simply not work if the reflection plane normal has components that add ...

Landscape Transparent with r.Lumen.DiffuseIndirect.Allow 0

UE - Graphics Tools - Terrain - Landscape - Jul 31, 2024

Implied Decal Blend Modes don't properly account for Material Attributes usage

UE - Rendering - Architecture - Sep 28, 2021

I've attached a project with the necessary materials that demonstrate this issue. I would expect that just because a Set Material Attributes node is inside a material graph it wouldn't affect the de ...

Having a block in layout before switching to overlay strategy affects the overlay output.

UE - Anim - Mutable - Mar 5, 2026

Issue: If "Resizable" Layout Strategy contains a block, it will influence the "Overlay" Layout Strategy. Expected behavior: When using "Overlay" Layout Strategy, it should disregard whatever the "R ...

Nanite Landscape Visibility Layer Crash

UE - Graphics Tools - Terrain - Landscape - Jun 10, 2026

Upon saving the level after creating the landscape and painting visibility, the editor crashes. When you restart the editor and load the level, you are greeted with a warning in the upper right corn ...

VisualizeTexture with the BMP flag causes a crash when any mip over mip0 is requested

UE - Rendering - Architecture - Dec 18, 2024

When a mip level higher than 0 is requested in VisualizeTexture, the engine will crash. The root cause appears to be VisualizeTexture.cpp:924, on which an incorrect mip level is used to read a non-m ...

[CrashReport][Crash] Engine!FSceneViewport::UpdateViewportRHI() [SceneViewport.cpp]

UE - Rendering - Architecture - RHI - May 29, 2026

#200 crash out of 2101 in UE 5.8 on Windows#34 crash for UE - Rendering - Architecture in UE 5.8 on Windows#20 crash for UE - Rendering - Architecture - RHI in UE 5.8 on WindowsAssertion failed: IsI ...

UnkownRef Mips can cause TextureStreaming peaks during loading

UE - Rendering - Graphics Features - Mar 27, 2023

UnkownRef Mips is meant to fix/workaround the problem where some textures are used for rendering but they don't have any component references them (such as texture used by PP effects) These UnkownR ...

FMassMoveTargetFragment::CreateNewAction does not update PreviousAction, breaking the start-of-path avoidance fade and related behavior for MassEntity crowds

UE - Runtime - Character - Jul 28, 2026

In MassEntity-based crowds, when an agent transitions from Stand to Move and begins walking, the Avoidance trait parameters StartOfPathDuration and StartOfPathAvoidanceScale, which are meant to temp ...

Lumen Card Sharing is active on material with custom primitive data

UE - Rendering - Graphics Features - Lumen - Aug 13, 2025

The wrong emissive value may be used on Nanite objects with custom primitive data when Lumen card sharing is enabled. This issue can be mitigated with: r.LumenScene.SurfaceCache.AllowCardSharing 0 ...