Unreal Engine Issues
Unreal Engine Issues
Actor Component properties can become "linked" across multiple Blueprints after a hot reload
UE - Gameplay - Components - Dec 3, 2018If code in an Actor Component class is changed (eg. a new UPROPERTY is added) and a hot reload is performed to implement the changes, the properties in the component can become linked across any Blu ...
GAS: AbilitySystemComponent does not DestroyActiveState after re-entering play
UE - Gameplay - Gameplay Ability System - Oct 30, 2023UAbilitySystemComponent::DestroyActiveState() is called when the component is unregistered (OnUnregister) and when its destroyed (OnComponentDestroyed). It performs state cleanup such as canceling a ...
Crashes after destroying a skeletal mesh attached via socket name (not bone name), the destroyed mesh remains welded.
UE - Runtime - Simulation - Jul 18, 2025On welding physics bodies during primitive component attachment, UPrimitiveComponent::WeldToImplementation() calls GetRootWelded() and then GetBodyInstance() on the returned root. This searches by b ...
[CrashReport] Assertion failed: !PinRef->bWasTrashed | UEdGraphPin::SerializePin()
UE - Gameplay - Blueprint - Aug 29, 2017This is a common and longstanding crash that has occurred since at least 4.15 and affected nearly 500 users. The CrashGroup was previously linked to [Link Removed], but that had specific repro step ...
When a BPActor containing HISMs is multiplied with a scale, LOD display control doesn't work correctly
UE - Rendering - Architecture - Nov 29, 2023Workaround 1: 1. Change HierarchicalInstancedStaticMesh.cpp in either of the following ways:void{{ FHierarchicalStaticMeshSceneProxy::GetDynamicMeshElements(const TArray<const FSceneView*>& Views, c ...
Iris - HitObjectHandle not resolved when receiving FHitResult
UE - Networking - Iris - Feb 12, 2026This seems to occur due to an interaction between how Iris handles serializing the FGameplayAbilityTargetData_SingleTargetHit struct and how the FActorInstanceHandle HitObjectHandle in the FHitResul ...
Out-of-bounds read caused by improper return size from FSocketSteam::RecvFrom in Unreal Engine
UE - Online - Jun 7, 2021Overview: Function at fault: FSocketSteam::RecvFrom (https://github.com/EpicGames/UnrealEngine/blob/c3caf7b6bf12ae4c8e09b606f10a09776b4d1f38/Engine/Plugins/Online/OnlineSubsystemSteam/Source/Private/ ...
Variant Manager: LevelVariantSets asset corruption after rename or duplicate
UE - Editor - Content Pipeline - Variants - Oct 24, 2025When renaming or duplicating a LevelVariantSets asset that contains a Director Blueprint, the internal DirectorClass reference becomes mismatched. Although the DirectorBlueprint pointer updates corr ...
Crash in GC - FSharedStruct reachability race condition
UE - Core - Systems - Jul 13, 2026This Jira was created from the linked EPS case: =============================================== This issue is caused by FSharedStruct batching reachability requests to the same underlying FInstan ...
Classes in TargetDenyList modules are still referenced from Components on BlueprintGeneratedClasses and cause runtime warnings
UE - Core - Systems - Feb 25, 2024Other than the presence of the error and the performance cost of looking for a package on disk that does not exist, there are no behavioral problems. When running with legacy (non-iostore) pakfiles ...