Unreal Engine Issues
Unreal Engine Issues
r.Shaders.Optimize=0 crashes when compiling a UI material
UE - Rendering Architecture - Materials - Sep 2, 2024[2024.08.30-22.12.22:384][ 73]LogWindows: Error: appError called: Assertion failed: CurrentGPUVirtualAddress != 0 [Link Removed] [Line: 659] Disabling shader optimisation can crash the editor when ...
Morph target normals not correctly applied when imported as LOD 0
UE - Editor - Content Pipeline - FBX - Nov 27, 2025This is a regression since 5.5 with skeletal meshes where morph target normal/tangent deformation only works when a mesh is imported as a LOD of an existing skeletal mesh, but not when imported as L ...
Outliner eye toggle fails to hide static meshes when Affect Indirect Lighting While Hidden is enabled
UE - Editor - Nov 5, 2025When a static mesh has the property Affect Indirect Lighting While Hidden enabled, toggling its visibility via the Outliner eye icon does not hide the mesh in the editor viewport. The actor remains ...
Foot Placement: Division by 0
UE - Anim - Gameplay - Jan 31, 2025static FVector PointDirectionPlaneIntersection(const FVector Point, const FVector Direction, const FPlane Plane) { return Point + Direction * ((Plane.W - (Point | Plane)) / (Direction | Plane)) ...
Biquad Filter is incorrect when bandpass is 1.0
UE - Audio - Signal Processing - Aug 20, 2024The bandwidth on the biquad loepass filter is cutting frequencies well below 20kHz when the bandwidth is 1.0. Slack convo: [Link Removed] Visualization:[Image Removed] ...
Wrong density calculation in UBodySetup::CalculateMass
UE - Simulation - Core - Sep 29, 2025Wrong density calculation in UBodySetup::CalculateMass. The licensee has provided the following analysis and suggested fix: In UBodySetup::CalculateMass, the following code is present: // physical ...
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, 2025We 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 ...
Level Instances appear at the origin on Linux cooks
UE - World Creation - Worldbuilding Tools - Level Instances - Aug 14, 2024Level Instances are spawned in the origin (0,0,0) after making a packaged build in Linux ...
Xcode 26/16.4 Metal Toolchain generates metallib's that are not compatible with iOS 16
UE - Platform - Apple - Sep 23, 2025Below is the error output from FirstPerson template as a C++ project: {+}../../../FirstPerson58CPP/Content/firstperson58cpp_sf_metal_es3_1_ios-metal_es3_1_ios.0.metallib, 5881486 bytes!2025-09-23 1 ...
SkyLight Leaking does not affect reflections when the SkyLight is static but static lighting is disallowed
UE - Graphics Features - Sep 10, 2025Reflections do not receive SkyLight leakage contribution from a static SkyLight when static lighting is disallowed. This is caused by the function UpdateSkyIrradianceGpuBuffer checking if the SkyLig ...