Exported Particle Emitter Tries to Reference Graphs of Original System

UE - Niagara - Dec 7, 2017

User reports that the bug was initially discovered in 4.18 and then reproduced in 4.16 project (attached). Per User: For some reason when exporting this emitter to any other system bugs out. When ...

Packaging fails after changing from Dynamic to Static Nav Mesh Runtime Generation

UE - AI - Feb 8, 2016

If you package with Runtime Generation set to Dynamic and then switch to Static and attempt to repackage, the packaging will fail with the following error message.[2016.02.08-16.18.14:511][217]MainF ...

Meshes with scaled root bones pop when entering simulation

UE - Runtime - Simulation - May 15, 2026

This issue is fallout from the changes in 33851494. Prior to that, we didn’t get the pop on beginning the sim. The problem appears to be that in USkeletalMeshComponent::PerformBlendPhysicsBones we ...

Visual Studio opens unnecessary windows when adding a new C++ class via the editor's interface

Tools - Oct 25, 2017

When adding a new C++ class to a project via the editor's interface, Visual Studio is opened but it ends up opening more than is necessary. Firstly, Visual Studio is opened without focus on the two ...

[CrashReport] UE4Editor_LevelEditor!FMulticastDelegateBase<FWeakObjectPtr>::RemoveAll() [multicastdelegatebase.h:81]

Tools - Oct 26, 2017

This is a trending crash in 4.18.0. One case of this callstack occurred in 4.17.1, but then numerous have occurred in 4.18. Users have not provided any descriptions of their actions when the crash ...

Tabbing out of exclusive fullscreen leaves the window & backbuffer in an incorrect state

UE - Editor - UI Systems - Apr 24, 2020

With windows 10 there has come some new swap chains, which unfortunately messes some things with regards to fullscreen up. We've fixed a bunch in the renderer (which would downright cause crashes), ...

Possible data loss/corruption when loading levels in editor

UE - Gameplay - Jul 18, 2018

Reported behavior: Given Level_A which contains object_X, where object_X references Level_BDeleting object_X causes AssetRenameManger to check if we need to patch up other levelsLevel_B is load ...

Failure to sign when packaging for iOS Distribution when using Remote Compile from a code project on Windows

UE - Platform - Mobile - Feb 20, 2019

Packaging for iOS Distribution from Windows using Remote Compile results in a failure during the signing portion. This seems to be caused by a hardcoded "false" for a property that is used to determ ...

SketchUp UV scale is not consistent for Datasmith imports.

TM - Interoperability - Dec 6, 2024

This is not a regression.  We have 2 issues here.  First we have different tiling for the different materials, since the way sketchup handles texture scale. They scale the UVs of the object instead ...

PCG sampling of RVT does only works when sampling the first texture layer

UE - Graphics Tools - PCG - Components - Dec 11, 2025

The logic for selecting a page table texture in FVirtualTexturePageTable::Initialize() uses the indexing for texture layers (index 0-7) to fetch from the page table textures (index 0-1). All RVT for ...