Crash in Middle of PIE with Level sequences and MRQ running

UE - Anim - Runtime - Mar 6, 2023

Repro Rate: 5/5 Tested this a few times and the crash seems to come in at different intervals, some had the prestreaming almost finished, then would crash. Working on a video to show crash to add ...

Mouse functionality breaks on Linux when game is full screen on multi-monitor setup

UE - Platform - Linux - Mar 1, 2016

When the game window is maximized on any monitor other than the left most monitor, the mouse will not interact with the game window. ...

Duplicated PCG Component instance resets overridden parameters to default

UE - World Creation - Procedural Tools - PCG Component - Jun 4, 2025

Context: Similar to parameters in the Material editor, PCG Graph Parameters are user created overridable values and can help create customizable graphs for a variety of situations. Problem: The l ...

bIgnoreAllPressedKeysUntilRelease behaves differently for triggers in EnhancedInputAction and triggers in InputMappingContext

UE - Gameplay - Input - Aug 10, 2023

For actions that are triggered on the Input mapping context, simply adding or removing an InputMappingContext with no related key override with the bIgnoreAllPressedKeysUntilRelease option will caus ...

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 - Gameplay - 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:/ ...