Duplicating / Moving (to another level) an actor with a Hierarchical Instanced Static Mesh component causes a crash

UE - Graphics Features - Nov 14, 2016

When you have an actor with a Hierarchical Instanced Static Mesh component that has a Static Mesh set and is populated with at least 1 instance and then duplicate it or move it to another level, it ...

Building for Gear VR Distribution fails due to missing Oculus lib

UE - Platform - XR - Jun 7, 2017

Users have reported that building for Distribution on Gear VR results in failure due to a missing Oculus library. The error they receive is as follows: UATHelper: Packaging (Android (ETC2)): [javac ...

ISM + WPO = broken motion vectors?

UE - Graphics Features - Nov 5, 2024

Instanced Static Meshes will have incorrect velocity if a Material uses World Position Offset. Fixed WPO in a material causes significant velocity on the ISM. This was also replicated in //UE5/Rele ...

Displaying Revision control history for a file ending in an "undo" of a revision can cause a crash

UE - Editor - Workflow Systems - Jun 18, 2024

This crash is caused by how source control history is managed and shown. In this specific case the source control software is Perforce. As written in the repro steps, it can happen to any uasset tha ...

Sampling Scene Texture in Custom Expression in Post Process Material Breaks Viewport UV

UE - Graphics Features - Apr 6, 2018

This issue does not occur in 4.18.3 but does occur in 4.19 and Main, making this a regression. Per user: I suspect there's an issue with custom expressions and sampling coordinates. It appears onc ...

[CrashReport] UE4Editor_BlueprintGraph!BlueprintActionFilterImpl::IsEventUnimplementable() [blueprintactionfilter.cpp:588]

UE - Gameplay - Blueprint - Jun 1, 2016

This crash has been reported through the 4.12 Previews and is continuing to occur in the 4.12.0 release. Additional information about this crash is not available at this time, however it may be the ...

The FNetNameMapping::GetUniqueName function appends numerical values to the end of the previous name instead of replacing the previous name's numerical value

UE - Gameplay - Blueprint Compiler - Feb 23, 2018

The GetUniqueName() function attempts to make sure that all node names are unique. For nodes that are used a large number of times, it adds a numerical value to the end of the name. Prior to 4.18, t ...

ModularGameplay and other runtime plugins have wrong LoadingPhase

UE - Gameplay - Jun 30, 2022

Plugins that provide blueprint-accessible libraries generally need to be set the PreDefault LoadingPhase so they can be properly loaded before game-specific data that loads early in the Default load ...

UV Flipping Mode Causes Stretching of Particles

UE - Niagara - Nov 17, 2017

If "UVFlipping Mode" under Rendering on the Required node of an emitter is set to anything other than "None," the particles can become stretched and distorted. As a workaround, I have discovered th ...

Crash When Assigning a Static Mesh to the "Sample Static Mesh" Module

UE - Niagara - Jun 28, 2018

When assigning a static mesh to the "Sample Static Mesh" module, the engine will crash as soon as you select a mesh and click "Fix Now". If the mesh already has CPU access enabled it will crash as s ...