Using Custom Primitive Data as Final Colour in a UI Material crashes the engine with a missing uniform buffer

UE - Rendering Architecture - Materials - Jul 3, 2024

Using custom primitive data as an input in a UI material causes the engine to crash in the RHI thread. The exact crash is "Missing uniform buffer at slot 1, stage SF_Pixel." at Engine\Source\Runtime ...

UV merging issue when merging meshes with multiple materials

UE - LD & Modeling - Modeling Tools - Mesh Editing - Jul 15, 2019

See https://udn.unrealengine.com/questions/505632/view.html for more details Repro: -Have a mesh with 3 sections and 3 materials, assign section 1 to material 1 and section 2&3 to material 3. -Pla ...

Dialog Subtitles randomly Disappear or Display out of Sync

UE - Audio - Sep 8, 2016

Dialog Subtitles display out of order or disappear when called to the screen. The users reporting the issue believe this could be due to the priority of the Sound Waves conflicting with one another ...

GameplayTag Query on Component Instance resets when reloading level

UE - Gameplay - Components - Jun 14, 2018

GameplayTagQuery variables - when inside of a component, are not saved. User notes: "Note that this does not occur if the ActorComponent is added in code in a native actor and that the actor at S ...

Oculus Touch Menu Button Input Not Received When Set In Action Mapping

UE - Platform - XR - Mar 9, 2020

The left menu button on Oculus Touch doesn't have it's input received when it is assigned to an action mapping. This looks like it stopped working after SteamVR was integrated into the engine. Foun ...

Marketplace plugins "missing precompiled manifest" on Mac

UE - Platform - Apple - Oct 12, 2021

Summary This issue was reported by a licensee via UDN. It appears that all of the plugins generate a "missing precompiled manifest" error when packaging a project on Mac in UE4.26.2.Licensee Platfor ...

[CrashReport] UE4Editor_UnrealEd!SaveWorld() [filehelpers.cpp:359]

Tools - Aug 31, 2016

This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Descriptions from users are provided below. Error message: Assertion failed: !bIsReentrant [L ...

Imported animation has one more frame than the original fbx

OLD - Anim - Jul 19, 2016

In UE4.12, imported animation has one more frame than the expected frame number. AS_AN_StepAnim_Test.fbx is 60 frame long animation(starts at frame 0, ends at frame 60). When imported to UE4.12, it ...

STAT_AI_BehaviorTree_InstanceMemory is sometimes wildly inaccurate

UE - AI - Jun 10, 2020

From the UDN thread: Turns out this is caused by the way this stat was implemented for the FBehaviorTreeInstance struct: 1) You call IncMemoryStats on construct, before the struct is populated with ...

Video material previews incorrectly on Mac

TM - Rendering - Apr 3, 2025

Received multiple reports of users on Mac computers experiencing issues previewing video materials in Twinmotion 2025.1. When adding video materials to the scene, the scale seems to be incorrect an ...