Geometry Collection (GC) fragments are affecting the Navmesh in wrong positions

UE - Simulation - Physics - Destruction - Dec 6, 2024

Geometry Collection (GC) fragments are affecting the Navmesh in wrong positions and the identified cause is wrong indexing. Once a GC breaks, it's fragments, when big enough, are creating islands in ...

Low-level memory tracking has negative values for "FMallocUnused" and "Untracked"

UE - Foundation - Core - Oct 6, 2020

"FMallocUnused" is immediately bellow 0. "Untracked" is reported to go below 0 after very long playtimes (over 36 hours). Reported in version 4.25.3(CL 13942748). Tested and found negative values f ...

When used with First Loop Start Frame Offset and Use Animation Blueprint, the character will alternate between the specified animation and the reference pose

UE - Anim - Anim in Engine - Jan 30, 2023

If you use StartFrameOffset set to 1 or higher in conjunction with the Use Animation Blueprint, the character's animation will be rough towards the end of the section. Specifically, it seems that th ...

Paper2D performance regression due to TArray resizing

UE - Graphics Features - Aug 16, 2019

We've noticed after upgrading our heavy Paper2D project to 4.22 that tilemap performance has been massively degraded compared to previous versions. After some digging we found out that it's due to a ...

Conflict between sequencer transform track and Parent Constraint from the Animation Mode breaks temporary pivot translation on any actor

UE - Anim - Anim in Engine - Jul 15, 2025

Note: This affects all versions from at least UE 5.3, including mainline latest. The "Animation" Editor Mode allows creating constraints for level actors. One of these, the "Parent" constraint, con ...

Bloom intensity broken with Post Processing Material replacing Tonemapper

UE - Graphics Features - Sep 25, 2020

When replacing the Tonemap using a Post Process material, the Post Process Volume's Bloom Intensity can only be turned on or off, without varying degrees of effect. Reported in version 4.25.3(CL 1 ...

Crash on map change with non-null values for GPropertyColorationClass and request customizable property coloration color

UE - Editor - Workflow Systems - Aug 7, 2023

This was found by a customer through a UDN, and they offered the fix for it, as well. The basic steps to reproduce the crash are as follows:call GEditor->SetPropertyColorationTarget(...) somewhere i ...

IAP failed to read purchase

UE - Platform - Mobile - Feb 20, 2017

In-app purchases do not seem to be working properly in Unreal Match 3 or other games ...

Soft angular constraints solve velocity like hard constraints

UE - Simulation - Core - Jul 17, 2025

Soft angular constraints are solving velocity like hard constraints. Instead of swinging back and forth, the affected body just snaps to 45 degrees. Check the steps to reproduce for more details. Th ...

Tiling Sprite in UMG uses whole image

UE - Editor - UI Systems - Sep 21, 2020

When a Sprite that has been created from a Texture Atlas is used in a Widget, it can not be tiled. Instead the whole Texture Atlas is tiled.  Reported in version 4.25.3(CL 13942748). Tested and fou ...