Blueprint - Crash when a function takes an event as a parameter

UE - Gameplay - Blueprint - Oct 10, 2016

Looks like maybe we aren't replacing the source delegate function (SignatureFunction) reference on the UDelegateProperty after recompiling the class - the function's owner name has the TRASHCLASS pr ...

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 ...

Hot reload breaks code based struct array used in blueprints

UE - Gameplay - Blueprint - Mar 21, 2016

When an array of a struct, defined in code, is used in a blueprint, preforming a hot reload after making changes to the class with the struct will cause the blueprint nodes relating to the struct be ...

Property Editors fail to import text values for FKeys within array/set/map containers when the key is identified by some valid non-alphanumeric characters

UE - Gameplay - Input - Oct 28, 2024

The FKey structure represents a user action input such as a keyboard key, a mouse button/wheel, or a gesture in VR. For the keyboard, it can represent any pressable key, such as letters, numbers, sy ...

Environment Query System (EQS): EnvQuery runtime template object can be created with a non-unique name, corrupting the EnvQueryManager cache

UE - AI - Aug 5, 2025

On file [Engine\Source\Runtime\AIModule\Private\EnvironmentQuery\EnvQueryManager.cpp:812], function UEnvQueryManager::CreateQueryInstance() uses StaticDuplicateObject() to create a new UEnvQuery* (d ...

Custom Time Dilation causes PhAT bodies to hover

UE - Simulation - Physics - Nov 5, 2015

Custom Time Dilation causes PhAT bodies to hover This is not only happening with vehicles like the original bug described. This is also happening with PhAT skeletal meshes that are moving. https:/ ...

Blueprint enum-to-string node returning inconsistent results across platforms

UE - Gameplay - Mar 5, 2020

Converting a C++ enum to a string should be a consistent result, however when running in the editor it returns the display-name value instead of the index value. This prevents C++ UENUMs from being ...

Bindless Textures do not mip stream as expected

UE - Rendering Architecture - RHI - Jan 29, 2025

Bindless textures do not appear to stream mip levels. This issue is separate from an already reported bindless virtual texture streaming issue. When the editor is freshly launched or when mip level ...

Blueprint actor reference breaks after hot reload

UE - Gameplay - Blueprint - Apr 21, 2016

Reference to a blueprint based on a custom class will break if changes are made to the parent class and a hot reload is performed. Error Displayed added to Callstack section. Workaround: Compiling ...

Division by zero in FAnimNode_StrideWarping::EvaluateSkeletalControl_AnyThread

UE - Anim - Gameplay - Sep 29, 2025

When an Actor's CustomTimeDilation is 0.0, functions FActorTickFunction::ExecuteTick() and FActorComponentTickFunction::ExecuteTickHelper() will call AActor::TickActor() and UActorComponent::TickCom ...