Crash When Changing to Landscape Paint Tool With a Material Function for the World Position Offset of the Landscape Material

UE - Graphics Features - Feb 25, 2019

Crash on switching to landscape/paint tab when using a landscape material that has a material function hooked onto the WorldPositionOffset. Working as expected in 4.21 CL# 4753647 Found in 4.22 CL ...

Invalid array length error launching QAGame onto HTML5

UE - Platform - Mobile - Mar 22, 2017

Firefox 32-bit Version 52.0.1 This error also occurs in MainRangeError: invalid array length[Learn More] 0943e4e3-83fc-4463-accc-9fd15fd7df6c:157:9 processPackageData blob:http://localhost:53501 ...

Instanced Actors: PCG on RuntimeGrid "None" assigns created IAManagers RuntimeGrid "MainGrid", causing cross-grid reference

UE - World Creation - Procedural Tools - PCG Graph - May 30, 2026

Context PCG can be used to spawn Instanced Actors via the PCG IA Interop plugin, that makes Spawned Instanced Actors available as node. When a PCGActor placed in the level runs a PCG graph that spa ...

Crash saving a destructible mesh after creating it from static mesh

UE - Simulation - Physics - Destruction - Sep 29, 2016

Crash occurs when saving a destructible mesh after creating it from a static mesh. ...

Editor cannot handle blueprint structure using an Actor Map variable

UE - Gameplay - Blueprint - Aug 28, 2017

If a blueprint structure contains a map variable with Actor Class Reference as the key, populating the map with a custom blueprint (ActorSet) and adding a variable of the structure to any other blue ...

Material expression If node has been broken, major regression that shipped in 4.6

UE - Graphics Features - Dec 9, 2014

This sounds legit. Anyone mess with the if node recently? There seems to be a regression where existing content is broken. This should be fixed ASAP and patched into 4.6. https://forums.unrealen ...

StructUtils plugin's `FInstancedStruct` in a CPP-defined struct in a `TArray` on an actor component defined in CPP and implemented in BP. Populating the instanced struct in an actor BP's class defaults breaks serialization of the class defaults.

UE - AI - May 30, 2025

Context Instanced structs are great for holding simple data with the main advantage they have is a low memory overhead unlike instanced objects. Problem The problem is in StructUtils plugin's `FIns ...

Crash Occurs When Switching Value on TMap

UE - Gameplay - Blueprint - Mar 15, 2017

The editor seems to be intermittently crashing when switching the value of a Map variable. I've only been able to get this to occur when switching from one type to a Vector at this time. ...

macOS build appears to hang due to UBT deadlocking on ps buffer

UE - Foundation - Cpp Tools - Apr 22, 2021

Licensee reports buffer deadlock issue in System/BuildHostPlatform.cs (lines 283-329). Moving Proc.WaitForExit() to after the for-loop seems to resolve the issue for them.publicoverride ProcessInf ...

OnComponentWake Event does not trigger when the physical body is awoken by a Force

UE - Simulation - Core - Feb 27, 2025

OnComponentWake Event does not trigger when the physical body is awoken by a Force. The steps described on Steps To Reproduce is enough to replicate this behavior. The OnComponentWake event is only ...