Children of editor-only actors do not maintain correct transforms when placed inside level instances for PIE and cooked builds

UE - World Creation - Worldbuilding Tools - Level Instances - Oct 20, 2025

We have found an issue where children of editor-only actors get wrong transforms in PIE and cooked builds when placed inside level instances. This affects both engine version 5.5 and 5.6. The issue ...

[CrashReport] Crash on Mac related to cooking for IOS

UE - Graphics Features - Jul 20, 2017

This is a common commandlet crash for Mac users in 4.16. In all cases, the command line is like: "(path/project).uproject" -run=Cook -NoLogTimes -TargetPlatform=IOS -fileopenlog -unversioned -ski ...

SteamVR turns off vsync globally

UE - Platform - XR - Feb 21, 2020

Additional Info From User: Result: Vsync will get turned off by FSteamVRHMD::Startup() setting a global console variable, regardless of your project configuration. Expected: Vsync is only deacti ...

Crash when trimming animation and then undoing action

UE - Anim - Runtime - May 30, 2023

Repro rate: 3/3 times This is a regression as the issue does not occur in 5.1.1  ...

Crash: Direct3DDevice->CreateBuffer failed at D3D11VertexBuffer.cpp with error E_INVALIDARG

UE - Graphics Features - Jul 6, 2017

This is a common crash affecting users since at least the 4.14 release. It was previously associated with [Link Removed], however that has been marked as fixed. Source Context 221 void Veri ...

Exception on missing file during GC in horde storage

UE - Foundation - Horde - Storage - May 7, 2025

During GC, if a file was manually deleted (but the storage system is still track), GC can erroneously fail (and never remove the reference). This causes a backup in GC, putting the whole algorithm i ...

[CrashReport] Assertion on in UMaterialInterface::InitDefaultMaterials()

UE - Graphics Features - Jun 28, 2017

This is a common Mac crash occurring in the 4.16.1 release. I have not found any evidence of it occurring on Windows. The callstack closely matches [Link Removed], which was briefly experienced by ...

Walking into some destructibles crashes the editor

UE - Simulation - Physics - Destruction - Aug 20, 2015

Submitted by a licensee on UDN. I verified it and have attached the test level that he provided. In the test map. some boxes fall and break. Walking straight into the boxes causes the editor to cra ...

NPC - Instances does not get updates from changes to the parent Niagara Parameter Collection in the editor

UE - Niagara - Oct 4, 2024

When an Niagara Parameter Collection (NPC) is selected as the parent Collection for an NPC Instance (NPCI), all of its current parameters are carried over to the NPCI with their current values as th ...

Niagara - When Interpolated Spawning is disabled, the first frame of each particle unexpectedly does not take into account the Particle Update stage

UE - Niagara - Feb 28, 2025

Foreword: Even if the behavior described here is by design, it is rarely (if ever) expected or desired. This was discussed and agreed to be treated as a bug. Explanation below. When interpolated sp ...