Editor Crashes when importing some FBXs with multiple Material IDs in 4.14.2

UE - Editor - Content Pipeline - Import and Export - Jan 5, 2017

This is a regression in behavior between 4.14.1 and 4.14.2! The editor will crash when importing FBX meshes that have multiple material ID assignments. If it's a single material ID it will import w ...

[CrashReport] UE4Editor_Renderer!FMaterialShader::VerifyExpressionAndShaderMaps() [shaderbaseclasses.cpp:148]

UE - Graphics Features - Jun 14, 2017

This is a common crash occurring in the 4.16 release. It is spread out across many different CrashGroups with slight variations in Callstack. Additional information is not available at this time. ...

Get Physics Linear Velocity node does not return the correct values in UE5

UE - Simulation - Physics - Nov 24, 2021

The Get Physics Linear Velocity node seems to only output a vector of 0.0, 0.0, 0.0 no matter what the velocity of the object it's measuring is.  Tested in //UE4/Release-4.27 @ CL 17735300 and th ...

A welded hierarchy blocks updates to collision settings on all but the root primitive. Calling SetCollisionResponseToChannel on the children won't work.

UE - Simulation - Physics - Nov 22, 2024

A welded hierarchy blocks updates to collision settings on all but the root primitive. Calling SetCollisionResponseToChannel on the children won't work. The licensee noticed that IPhysicsProxyBase* ...

Level Bounds Calculated Incorrectly when using Particle System Components

Tools - Nov 20, 2016

If an Actor blueprint contains a particle system component (PSC), the Level bounds behave differently based on if the particle template is / is not Null. If the template is Null, Level Bounds stret ...

Lumen Card Sharing is active on material with custom primitive data

UE - 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 ...

Editor numeric input fields don't support double precision numbers.

UE - Editor - UI Systems - Aug 9, 2024

Even if we support double precision numbers at core, it's impossible to enter a small number in the numeric fields.  It makes sense for floats and avoids bloating the UI, but I remember a discussio ...

[CrashReport] FMacWindow::ApplySizeAndModeChanges | SWindow::ReshapeWindow()

UE - Platform - Apple - Dec 1, 2017

This is an infrequent Mac crash in 4.18. Users have not provided any descriptions of their actions when the crash occurred. The callstack is similar to both [Link Removed] and [Link Removed] Call ...

Unwanted black boundaries are displayed in a vertical split-screen with 3 players.

UE - Gameplay - Dec 2, 2019

Floating point error from UGameViewportClient::SplitscreenInfo causes this issue. FMath::TruncToInt( 3240 /*ViewportSize*/ * 0.333f/*Ratio in SplitScreenInfo*/ ) = 1079 I suggested a following t ...

PrimaryAssetLabel Assets are getting stripped from ShooterGame on the Launcher

UE - Foundation - Build - Rocket (Installed Engine) - Aug 7, 2017

PrimaryAssetLabel assets are missing when creating the project through the UE4Launcher, they exist in Source builds. The ShooterGame PrimaryAssetLabel assets were created in 4.16 so this is not a r ...