Niagara - When Interpolated Spawning is disabled, the first frame of each particle unexpectedly does not take into account the Particle Update stage

UE - Niagara - Feb 28, 2025

Foreword: Even if the behavior described here is by design, it is rarely (if ever) expected or desired. This was discussed and agreed to be treated as a bug. Explanation below. When interpolated sp ...

Precomputed Visibility no longer calculated on Landscapes

UE - LD & Modeling - Terrain - Landscape - Jun 24, 2015

Placing a Precomputed Visibility Volume around or through a landscape does not seem to calculate precomputed visibility for that landscape. This is a regression from behavior in 4.7.6. Also Tested ...

UV Rotation does not work for video materials

TM - Rendering - Dec 9, 2024

The rotation parameter of video materials does not function in Twinmotion 2024.1.2 and Twinmotion 2025.1 PR. Adjusting the slider does not have any effect. Feature last worked in Twinmotion 2023.2 ...

Crash when changing r.MaterialQualityLevel when FastGeo plugin enabled in cooked build

UE - World Creation - Worldbuilding Tools - Sep 5, 2025

The engine crashes when the r.MaterialQualityLevel is changed in a cooked game that uses the FastGeo Streaming Plugin. The crash doesn't repro with the same steps in Editor, just in a cooked build. ...

Debug Helpers no longer drawn indefinitely if life time is set to 0 or less

UE - Graphics Features - Sep 10, 2018

Setting the lifetime for one of the visual debug helpers (a sphere was used in the repro, but the results should be similar for any of the debug helpers) to a value of 0 or less should make the debu ...

(GAS) Block tags are ignored in version 5.5.2 if two abilities share the same parent tags structure.

UE - Gameplay - Gameplay Ability System - Feb 5, 2025

Block tags are not working correctly in version 5.5.2, it was working in 5.5.1. This is caused by a change done in version 5.5.2. The exact CL is: CL 35930696 ...

Raytraced reflection doesn't work with high roughness

UE - Graphics Features - Lumen - Oct 30, 2020

Even when the max roughness for raytraced reflections is set to 1, they seem to be blended away at far below that value. For projects (e.g. film,vfx) where quality trumps speed it would be valuable ...

Editor crashes when right clicking .csv data table

UE - Gameplay - Dec 24, 2014

Right clicking a csv data table in content browser crashes editor. Frequency: 3/3 CrashReporter: [Link Removed] Callstack: MachineId:4E82586D46B558EA69EF0EAA821297B1 EpicAccountId:1558531203f8 ...

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 ...