Crash in Debug Camera (patch provided in comment !)

UE - Gameplay - Feb 12, 2019

Hello, A licensee has reported us a crash in DebugCameraController / DebugCameraHUD.  It is due to a missing check in ADebugCameraHUD::PostRender() of SelectedActor set in ADebugCameraController ...

Instanced static meshes fire an erroneous performance assert about loose parameters.

UE - Graphics Features - Sep 4, 2019

 "This ensure is intended to catch regressions where rendering programmers add a loose parameter to LocalVertexFactory, breaking dynamic instancing on regular static meshes.  InstancedStaticMeshes c ...

All ELinearConstraintMotion pins in BP reset to "Free" when converting a project to 4.26

UE - Simulation - Physics - Feb 24, 2021

When using any of the Set Linear Limit nodes (X/Y/Z) and converting a project from a previous version of the engine, the nodes get their Constraint Type value reset to Free. I tested this with proje ...

Game View renders Lights with Actor Hidden In Game enabled

UE - Graphics Features - Dec 6, 2022

This is not a regression. Tested in both 4.27.2 and //UE5/Release-5.0 CL20979098 Game View renders Lights with Actor Hidden In Game enabled. Documentation states: "...the Viewport to display the sc ...

BP timelines: when converting internal curve to external, the external curve isn't used until BP is recompiled

UE - Framework - Blueprint Editor - Aug 28, 2023

Blueprint timelines: when converting an internal curve to an external curve asset, the curve asset's data isn't used until the blueprint is recompiled. This is confusing as there is no indication th ...

'GetClassDefaults' Can Cause Blueprint To Become Modified When Unrelated Blueprint Is Compiled

UE - Gameplay - Blueprint - Sep 22, 2023

The stems from a really old change (CL 2948683) to fix [Link Removed]. Compiling ObjectA will call RefreshExternalBlueprintDependencyNodes on its dependent BP,  ObjectB_ReferencesA, which reconstru ...

Local Exposure can cause large variations in PreExposure under certain conditions

UE - Graphics Features - Sep 16, 2025

PreExposure is influenced by LocalExposure in PostProcessEyeAdaptation.cpp:1265. It appears when the scene is particularly dark and using manual exposure, the LastAverageLocalExposure can read a lar ...

XAudio2 DestroyVoice call causes significant hitching on some architectures

UE - Audio - Aug 10, 2015

Another thread: https://answers.unrealengine.com/questions/241358/amd-cpu-very-low-performance-because-ixaudio2sourc.html Note: This not a regression and has existed since our first implementation ...

Packaged projects do not render in web page using Safari 10.0

UE - Platform - Mobile - Aug 9, 2016

My Macbook Pro uses an Nvidia GeForce 750M and was on Safari 10.0 when this occurred. This did NOT occur on a Macbook Pro with the same card and using Safari 9.1.2. This did NOT occur on an iMac wi ...

User created widgets from widgets that are normally not focusable appear to break navigation when added to another widget even when focusable set to true

UE - Editor - UI Systems - Oct 28, 2016

User created widgets from widgets that are normally not focusable appear to break navigation when added to another widget even when focusable set to true Example: A widget with only a text block in ...