Unreal Engine Issues
Unreal Engine Issues
Mover MoveDirectionIntent can be 0 due to interpolation
UE - Gameplay - Player Movement - Apr 22, 2025If two states have MoveDirectionIntent vectors that are opposite to each other, interpolating between these states can result in MoveDirectionIntent being 0. This may cause issues for animation blue ...
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 ...
Reflections of Masked Materials incorrect with Lumen HWRT and Max Refraction Bounces > 0
UE - Graphics Features - Lumen - Dec 18, 2025Lumen HWRT Reflections of Masked Materials are incorrect when "r.Lumen.Reflections.HardwareRayTracing.Translucent.MaxRefractionBounces" is greater than 0. The same issue occurs if the Post-Process V ...
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 ...