FNiagaraScalabilityManager incorrectly reactivates a NiagaraComponent that was deactivated by runtime user code

UE - Niagara - Scalability - Oct 1, 2025

Context: The Niagara System is the primary tool to do visual effects inside Unreal. Niagara systems can be culled due to distance. Problem: Once a deactivated Niagara System is culled due to distan ...

Bloated instruction counts in the material editor causing long compiles

UE - Graphics Features - Apr 17, 2019

artists are dealing with greatly increased iteration times due to long shader compiles when working in the material editor. This has regressed over time as we add more features to the point were wor ...

Some textures stretched on Mobile device

UE - Platform - Mobile - Sep 8, 2015

User's content is here: "P:\temp\UrbanJogging.zip" "If you start up the game or go into the content, the issue is on Track One, on the first bend on the right. Also be careful with the sprint bu ...

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

UE - Graphics Features - Oct 26, 2017

This Jira is for the continuation of the "D3D HUNG" crashes which originally spiked in the UE 4.14 release. Some fixes were implemented in 4.16.2 and 4.17.0 which made some improvement to the freque ...

[CrashReport] UE4Editor_PropertyEditor!SDetailSingleItemRow::OnArrayDrop() [sdetailsingleitemrow.cpp:172]

Tools - Oct 10, 2017

This is a trending crash coming out of the 4.18 previews. Users have not provided any descriptions of their actions when the crash occurred. The callstack shares similarities to [Link Removed] whi ...

BlendSpace DeltaTimeRecord.Delta can incorrectly be set to zero

UE - Anim - Runtime - Apr 19, 2024

It's possible for blendspaces to end up with an invalid delta time record because of how UBlendSpace::TickAssetPlayer modifies the time record.  This only seems to happen with specific settings:Axis ...

Crash when changing a Play Node's "Sequence" to a Montage

OLD - Anim - Jan 20, 2016

I understand that this is not something you're intended to be able to do (Montages aren't used this way), but we should bar the user from inserting a montage into this variable slot. Crash occurs w ...

SpringArmComponent with "Use Camera Lag Substepping" does not handle fluctuating frame rates correctly

UE - Gameplay - Jun 4, 2024

The description of SpringArmComponent's "Use Camera Lag Substepping" option says "sub-step camera damping so that it handles fluctuating frame rates well". However, as noted and explained by a licen ...

Collision profiles are reset when blueprint is loaded

UE - Gameplay - Jan 6, 2025

In UE 5.5 (and earlier versions), FCollisionResponse::operator== has incorrect behavior where it will detect that two collision response containers are identical if they have the same number of entr ...

Dangling pointer + mem corruption related to OwnerLastRenderTimePtr

UE - World Creation - Worldbuilding Tools - Mar 16, 2026

We've been seeing asserts and crashes related to OwnerLastRenderTimePtr. We've traced this to the mentioned pointer ending up dangling after using UActorComponent::Rename() on primitive components t ...