Incorrect CRC hash for shared fragments with FInstancedStruct member

UE - Engine Scaling - Mass - Mar 30, 2026

User has encountered an issue with shared fragments that contain a member variable of type FInstancedStruct. It appears that UE::StructUtils::GetStructInstanceCrc32() does not correctly compute the ...

Changing blueprint default values inside arrays only updates loaded child blueprints

UE - Core - Systems - Jul 30, 2020

The rules for delta serialization in UE4 are complicated, and the editor tries to hide them from you, which works 90% of the time but can lead to confusion and data loss in other situations. In the ...

changing localization does not change text in PIE

Tools - Sep 10, 2015

When switching localization for testing, text does not change language in PIE. ...

GAS: GameplayCueNotify OnActive executed twice for Duration GEs on Standalone+ListenServer

UE - Gameplay - Gameplay Ability System - Aug 2, 2023

When playing Standalone or as Listen Server, whenever a GameplayEffect with a duration is applied that fires gameplay cues, the server will locally execute OnActive twice on GameplayCueNotify_Actors ...

AbilitySystemComponent::NotifyAbilityEnded Can Crash due to Callbacks Invalidation Specs

UE - Gameplay - Gameplay Ability System - Oct 11, 2023

Pasting from the UDN: Unsafe code in AbilitySystem can lead to crash when granting an ability inside OnAbilityEnded Hello. We just ran into a crash. After investigation, it seems to be caused by ...

Cannot Use Key Value Combo "Alt + F4" for New Action Mapping

UE - Gameplay - Input - Apr 21, 2016

You cannot use the key value combo "Alt + F4" as the input for an Action Mapping, whereas you can use "Alt + other F keys" as inputs. (Alt + F4 is a command to close programs in Windows) Expected: ...

LevelStreamingPersistence: BP variables that aren't Instance Editable get reset

UE - World Creation - Worldbuilding Tools - Mar 6, 2026

Context The LevelStreamingPersistence plugin can be used to remember and restore properties on actors and components that are part of a streamed level. Blueprint variables can be marked as instan ...

Framerate drops when using SceneCaptureComponents with a RenderTarget in VR

UE - Platform - XR - May 14, 2018

Using SceneCapture in packaged VR projects causes poor performance. Also observed with SceneCaptureCube Does not occur in 4.18 ...

Blueprint Projects can't make APK without compiled .so Error when packaging for Android with any Plugin Disabled

UE - Platform - Mobile - Sep 5, 2018

Blueprint Projects can't make APK without compiled .so Error when packaging for Android with any Plugin Disabled. Also seeing Gradle errors if SteamVR plugin is disabled. Setting min version to 14 ...