Struct with a single unaltered element will remove the element from the struct on compile

UE - Gameplay - Blueprint - Oct 7, 2015

If used inside a UMG Blueprint, a struct that has only one element will remove the element from the struct after compiling the blueprint. If the element is edited or a second element is added then ...

Blueprints not marked dirty when variables in referenced actors are renamed

UE - Gameplay - Blueprint Compiler - Feb 20, 2018

Blueprints using renamed variable do not indicate that they need to be recompiled. (However errors are shown on play) It is possible to not see an error if you add a variable with the same name as ...

Crash in NaniteStreamManager when Nanite data fails to decode corrupt data from DDC

UE - Graphics Features - Nanite - Sep 11, 2024

If Nanite data becomes corrupt in the DDC, the Editor may crash in FStreamingManager::InstallReadyPages() when the Pending.State is FPendingPage::EState::DDC_Ready but the resulting SrcPtr is null b ...

Android ETC2 Debug Builds Crash on Startup

UE - Platform - Mobile - Sep 9, 2020

Android apps build with the debug configuration on ETC2 will crash on launch. ...

Crash during garbage collection when container UPROPERTIES specify raw interface pointer element types without TScriptInterface wrapper

UE - Foundation - Cpp Tools - UnrealHeaderTool - Oct 1, 2024

When a UPROPERTY() TMap or TArray has raw interface pointers as element type, the garbage collector tries to handle them and crashes. For raw interface pointers without a container, UHT generates a ...

In a Geometry Collection, enabling Nanite Fallback in a Nanite Enabled collection won't generate a Physics Body when Nanite is disabled

UE - Simulation - Physics - Destruction - Jun 30, 2025

In a Geometry Collection, enabling Nanite Fallback in a Nanite Enabled collection won't generate a Physics Body when Nanite is disabled. To verify this, follow the steps provided in the Steps to Re ...

Editor crashed when opening TM-MeshPaint in QAGame

UE - Graphics Features - Jan 20, 2017

While reviewing [Link Removed] test case, I hit the following crash opening the TM-MeshPaint level. On first attempt shaders were compiling, on attemps after, editor crashes much faster. ...

BP - Nativization will fail at cook time if a BP class and a User-Defined Structure reference each other.

UE - Gameplay - Blueprint - Apr 20, 2017

Note: This happens with "Exclusive" nativization mode as well. This occurs because the nativized UDS 'GetDefaultValue()' method is generated into a .h file rather than a .cpp file. This creates a c ...

Project breaks if Online Subsystem plugin is disabled

UE - Foundation - Core - Apr 25, 2017

Disabling Online Subsystem prevents the project from loading. On Windows, this produces an error shown in attached screenshot. On Linux, this causes a crash with the attached callstack on project ...