Unreal Engine Issues
Unreal Engine Issues
UMG widget callbacks do not set PIE context in editor
UE - Editor - UI Systems - May 21, 2018This is from a UDN post. Several gameplay functions, such as level streaming and SoftObjectPtr resolution, depend on the GPlayInEditorID being set when that code is executed in PIE in the editor. T ...
Nanite: unused VertexInterpolator node disables Opacity Mask (material renders opaque)
UE - Rendering - Architecture - Jun 8, 2026On Nanite meshes, placing a VertexInterpolator node in a material graph without using it (unconnected, or routed through a disabled static switch) silently breaks the Opacity Mask and the material r ...
[CrashReport] UE4Editor_MeshPaint!FBaseMeshPaintGeometryAdapter::GetVertexPosition() [basemeshpaintgeometryadapter.cpp:70]
UE - Simulation - Physics - Character - Nov 2, 2017This is a trending crash coming out of 4.18, and may be a regression. Users have not provided any descriptions of their actions when the crash occurred. Source Context 57 const TArray<FVec ...
UE5.6+ - Mutable - IDPrefix crash when combining Child Objects, Add to Mesh Component and Extend Mesh Section.
UE - Runtime - Mutable - Jul 21, 2025So the issue seems to be a combination of Add To Mesh Component and Extend Mesh Section. I've tried this in Epic Launcher 5.6, 5.6 in-house modified engine as well as ue5-main 5.7 from git (editor ...
Buffer Visualization Overview is affected by EV
UE - Graphics Features - Mar 5, 2020EV -0.5 [Image Removed] EV 0.0 [Image Removed] ...
OpenGL: Nvidia: Crash when using foliage tool
UE - Platform - Linux - May 7, 2015As reported by user, using foliage tool in a first person project eventually crashes it. "Currently, any attempt to render objects created with the foliage tool crashes the UE4 editor on my machine ...
Fracture Mode > "Remove-On-Break" setting: Cluster Crumbling causes flickering
UE - Runtime - Deformable - May 10, 2025Fracture Mode > "Remove-On-Break" setting: Cluster Crumbling causes flickering. Once the Remove-On-Break Cluster Crumbling effect is activated, there is a small delay between the disappearance of th ...
Crash when removing and re-adding instances to an InstancedStaticMeshComponent with PerInstanceCustomData.
UE - Engine Scaling - Streaming - Jan 22, 2026When using an InstancedStaticMeshComponent with PerInstanceCustomData, the number of float elements in the "Custom Data" array should always be equal to NumCustomDataFloats multiplied by the number ...
Mac editor mobile preview crash with MSAA on
UE - Platform - Mobile - Mar 1, 2021setting GSupportsTimestampRenderQueries=false or r.GPUStatsEnabled=0 can fix it ...
Constant Crashes on OS X 10.10.1
UE - Platform - Apple - Dec 15, 2014User (Omri) on Mac running OS X 10.10.1. on MacBook Pro (17-inch, Early 2009 Experiencing Crash. Cannot reproduce. Crash Reporter: N/A Callstack: MachineId:1E07B9CE2F4554A7C3F421A9DD97AFB5 EpicAc ...