Niagara Mesh Renderer registers NumParticles x NumMeshVariants TLAS instances

UE - Rendering - Graphics Features - Ray Tracing - May 28, 2026

When using the Niagara Mesh Renderer with multiple mesh variants selected via MeshIndex, the number of TLAS instances allocated is NumParticles × NumMeshVariants and enabling the Path Tracer can ca ...

Regression: Several project settings, especially from built-in Plugins, are being silently erased when previously they were not, which is perceived as a bug

UE - Foundation - Feb 28, 2025

In UE's Project Settings, some pages are saved automatically to the project's "Config/Default<CATEGORY>.ini" file (meant to be version-controlled) on every change. Other pages have buttons "Set as D ...

[CrashReport] UE4Editor_D3D11RHI!TerminateOnDeviceRemoved() [d3d11util.cpp:176]

UE - Graphics Features - Nov 18, 2016

Error message: Fatal error: [Link Removed] [Line: 176] Unreal Engine is exiting due to D3D device being lost. (Error: 0x887A0006 - 'HUNG') Source Context: 161 162 const TCHAR* Rea ...

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 ...

[CrashReport] UE4Editor_LevelEditor!FLevelEditorActionCallbacks::Paste_CanExecute() [leveleditoractions.cpp:1602]

UE - Gameplay - Blueprint - Jan 17, 2017

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: GEditor->GetSele ...

Hot reload causes placed actor to lose variable references

UE - Foundation - Cpp Tools - Hot Reload - Nov 9, 2017

Preforming a hot reload causes placed actors to lose code based variable settings. More repro steps: 1. Open UE4Editor.exe 2. Create a First Person Code project 3. Build the project for Developme ...

5.5 Static Mesh Import Pipeline Regression

UE - Editor - Content Pipeline - Import and Export - Apr 25, 2025

This question was created in reference to: [Link Removed] This post references the first post because this problem was not discovered till now. I think it was masked because the issue appears to be ...

Ongoing D3D 'HUNG' crash in FD3D11DynamicRHI::GetQueryData

UE - Graphics Features - Jan 18, 2017

This is a new ticket for the D3D 'HUNG' crash originally reported in [Link Removed]. Some fixes were introduced in 4.14.2 that decreased the occurrences of this crash, but other cases are still ongo ...

[CrashReport] UE4Editor_D3D11RHI!VerifyD3D11Result() [d3d11util.cpp:200]

UE - Editor - UI Systems - Slate - May 9, 2016

This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Error message: Fatal error: [Link Removed] [Line: 200] SwapChain->ResizeBuffers(1,SizeX,SizeY ...

[CrashReport] UE4Editor_Landscape!FLandscapeEditDataInterface::SetAlphaData() [landscapeeditinterface.cpp:2617]

UE - LD & Modeling - Terrain - Landscape - Sep 8, 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: Access violation - code c0000005 ( ...