FCDODiffControl doesn't properly account for lists of differing size.

UE - Gameplay - Blueprint - Sep 21, 2016

FCDODiffControl doesn't properly account for lists of differing size. The issues are marked in the following code:int IterOld = 0; int IterNew = 0; while (IterOld != OldProperties.Num() || IterNew ...

TickComponent and PostPhysicsTick in SkeletalMeshComponent can cause simultaneous read/write access

UE - Anim - Runtime - Jan 18, 2023

When a SkeletalMeshComponent is restarted by calling in order of   SetSimulatePhysics and SetComponentTickEnabled, the TickComponent and EndPhysicsTick are executed simultaneously. As a result, the ...

Crash due to D3D device being lost. (Error: 0x887A0006 - 'HUNG')

UE - Graphics Features - Feb 22, 2017

This JIRA has been made to consolidate all "D3D device being lost. (Error: 0x887A0006 - 'HUNG')" crashes into one. Previous Jira tickets include:[Link Removed][Link Removed][Link Removed][Link Remo ...

Packaging for HTML5 seems to have grown in package size

UE - Platform - Mobile - Aug 30, 2016

The size of packages for HTML5 has greatly increased since 4.10.4 to 4.11.2 and has since increased. Example: First person template, no starter content - size of whole HTML5 folder once packaged: 7 ...

Crash on inputting Scalar Value in Grass Material Node

UE - LD & Modeling - Terrain - Landscape - May 6, 2015

Crash occurs when inputting a Scalar Parameter into the New to 4,8 Grass Node. Also reproduced in Main Promotable-CL-2535351 ...

SAnalogSlider moves slowly when step size is large

UE - Editor - UI Systems - Slate - Mar 6, 2024

SAnalogSlider calculates FastestStepTime by multiplying the step size value by a constant, resulting in high numbers for larger step sizes. This gets lerped from 1 and used as the repeat time, resul ...

Linux crash when Exporting content

Tools - Jun 2, 2016

When the ExportAll window is opened, changing the file type filter and attempting to edit the chosen file field causes the editor to crash. ...

BP timelines: when converting internal curve to external, the external curve isn't used until BP is recompiled

UE - Framework - Blueprint Editor - Aug 28, 2023

Blueprint timelines: when converting an internal curve to an external curve asset, the curve asset's data isn't used until the blueprint is recompiled. This is confusing as there is no indication th ...

Setting a struct bool property (bitfield) to itself writes the wrong value

UE - Framework - Blueprint Compiler - Sep 17, 2025

There's an issue when assigning a bitfield bool to a native bool in Blueprints. Currently, the engine erroneously treats the memory for a local bool as a uint8 bitfield, which is undefined behavior. ...

SetCollisionProfileName and SetCollisionEnabled aren't working in Construction Script

UE - Simulation - Physics - Dec 5, 2019

This is a regression from 4.22.3 (CL-7053642) where this setup executed as expected. Toggling Collision Profiles in 4.23.1 (CL-9631420) and onward do not affect the Static Mesh and it acts as if it ...