Mover MoveDirectionIntent can be 0 due to interpolation

UE - Gameplay - Player Movement - Apr 22, 2025

If 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 ...

Foot Placement: Division by 0

UE - Anim - Gameplay - Jan 31, 2025

static 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, 2024

The 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, 2025

Wrong 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, 2025

We 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, 2024

Level Instances are spawned in the origin (0,0,0) after making a packaged build in Linux ...

SkyLight Leaking does not affect reflections when the SkyLight is static but static lighting is disallowed

UE - Graphics Features - Sep 10, 2025

Reflections 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 ...

Insufficient precision of Decode71 function

UE - Rendering Architecture - Shaders - Jun 5, 2025

Encode71 and Decode71 in DeferredShadingCommon.ush are functions that convert 8-bit values ​​to 7-bit values ​​and mask values, and licensees have reported that the accuracy is insufficient when usi ...

Replicated subobjects list crashes with unreachable yet valid objects when UE_NET_SUBOBJECTLIST_WEAKPTR=0

UE - Networking - May 8, 2023

This seems to occur when the subobject is considered unreachable but is not yet pending kill/marked as garbage. In this case, IsValid returns true while FWeakObjectPtr::Get returns nullptr for the o ...