Behavior Tree (BT) services added to root nodes call the initial tick twice

UE - AI - Nov 20, 2024

Behavior Tree (BT) services added to root nodes call the initial tick twice A BT Service with the setting "Call Tick on Search Start" enabled will execute the initial tick twice when added to the ro ...

Editor crashes due to a material that contains MPCs migrated from another project

UE - Rendering - Architecture - Materials - Apr 29, 2024

[2024.04.29-16.49.46:563][970]LogUObjectGlobals: Warning: LoadPackage can't find package /BEURRE_040824_041224/NewMaterialParameterCollection. [2024.04.29-16.49.46:563][970]LogUObjectGlobals: Warning ...

Error maximum ps_5_0 sampler register index (16) exceeded on some materials in InfiltratorForward

UE - Graphics Features - Dec 13, 2016

Certain materials no longer compile in InfiltratorForward with Forward Shading enabled. These materials were not having this compile issue in //UE4/Main @ CL - 3231640 which is the CL before Dev-Ren ...

Lightmass: Blocky lightmap artifacts appears on the Mesh Actor which is shadowing by a single face mesh

UE - Graphics Features - Lumen - Jun 9, 2020

Begin Map Begin Level Begin Actor Class=/Script/Engine.StaticMeshActor Name=Plane_2 Archetype=/Script/Engine.StaticMeshActor'/Script/Engine.Default__StaticMeshActor' Begin Object Class=/Script/En ...

Double to float conversions of time in renderer causes precision issues

UE - Rendering - Architecture - Materials - Apr 8, 2026

In game sessions when the value for world time becomes large enough we start running into floating point precision issues. These issues can easily be seen in materials which do periodic animation b ...

Search field in 'Quickly Add to Project' fails with Chinese Pinyin input unless manually focused

UE - AI Workflows - UI Systems - Localization - May 28, 2025

A licensee reported that under the Chinese language setting in UE5, using the “Quickly Add to Project” button results in incorrect or ignored input when entering text via Pinyin IME. If the user sta ...

Fracture Mode > "Remove-On-Break" setting: Cluster Crumbling causes flickering

UE - Runtime - Deformable - May 10, 2025

Fracture Mode > "Remove-On-Break" setting: Cluster Crumbling causes flickering. Once the Remove-On-Break Cluster Crumbling effect is activated, there is a small delay between the disappearance of th ...

[MetaSounds][Sine Generator] - Ensure in MetasoundEnum.h

UE - Audio - MetaSounds - Mar 25, 2022

Live Ensure seen in Crash Reporter. Crash Reporter Link: [Link Removed] Hit 13 times by 4 users.Ensure condition failed: Converted [File:D:\build\++UE5\Sync\Engine\Plugins\Runtime\Metasound\Source\ ...

Crash when changing a Play Node's "Sequence" to a Montage

OLD - Anim - Jan 20, 2016

I understand that this is not something you're intended to be able to do (Montages aren't used this way), but we should bar the user from inserting a montage into this variable slot. Crash occurs w ...

Crash when building lighting while in PIE

UE - Graphics Features - Feb 21, 2017

NOTE: This issue is similar to (same callstack) as [Link Removed], however this issue is still occurring in 4.15.0. Error Message: Access violation - code c0000005 (first/second chance not availab ...