Unreal Engine Issues
Unreal Engine Issues
D3D12 uses a lot more memory than D3D11
UE - Graphics Features - Nov 4, 2015We’re aware of some extra memory usage in the DX12, but 100% more is more than we’ve seen! I think it’s multiple sources that is causing the increase in usage but not all are known. For example, I’v ...
Compilation error when using Particle SubUV in Niagara Mesh Particles with Raytracing enabled.
UE - Niagara - Oct 12, 2021The licensee has shared the following workaround for modifying NiagaraMeshVertexFactory.ush. struct FVertexFactoryInterpolantsVSToPS { TANGENTTOWORLD_INTERPOLATOR_BLOCK #if USE_PARTICLE_SUBU ...
Updates to DesiredFocusWidget for a UserWidget are not propagated to existing instances of it inside the WidgetTree of other widgets
UE - AI Workflows - UI Systems - Nov 17, 2025This issue has been reproduced in UE 5.3 to 5.7 and source versions. A repro project is available. Below are the findings from an initial investigation of the problem. Normally, when a UserWidget p ...
Crashes when attempting to use an Instanced Struct inside Control Rig / Rig VM
UE - CAPT - Control Rig - Mar 17, 2025Currently, the Control Rig Editor allows the user to use the "Instanced Struct" type, for example for a variable or function input/output. However, this type does not seem to be properly supported ( ...
FStateTreeExecutionContext::GetDebugInfoString() outputs wrong info and crashes when using linked state trees
UE - AI - Debugging - Apr 17, 2025When using State Trees, the AI Debugger can be accessed during play to show information about their current execution state. If a behavior tree is currently in a state that references a linked tree, ...
Getting Fullscreen or Windowed Resolutions doesn't fully execute on Linux
UE - Rendering - Architecture - RHI - Oct 28, 2019When using "Get Supported Fullscreen Resolutions" on UE when built with Vulkan, no values are printed out. This is an issue with any platform that builds UE with -vulkan, not just Linux. In Engine ...
Vive Trackpad X and Y always return 0
UE - Platform - XR - Feb 3, 2020Platform-specific input for pad axis in 4.24 leads to missing value in VIVE. in 4.23.1 this is not reproduced. ...
Crash when saving after resetting Instanced array element via Property Matrix on placed actors
UE - Editor - Nov 21, 2025When an Actor Component contains an Instanced UObject array marked EditDefaultsOnly, adding a new element to the Blueprint defaults correctly updates the Blueprint and its own Property Matrix. Howev ...
Blueprint processing is heavy in PIE since 4.26
UE - Gameplay - Blueprint - Feb 17, 2021As the attached image shows, there is no problem in 4.25.4, and the process is noticeably slower in 4.26.1. Also, there is no problem in Standalone. The problem occurs only in PIE. ...
Volumetric Clouds High Quality Aerial Perspective Issue
UE - Rendering - Architecture - Oct 19, 2023There is a workaround to set r.VolumetricRenderTarget.Mode=1. The lines appear to be coming from the temporal component of the Volumetric Clouds. Each frame, the lines are merged in from the previou ...