OnActorSpawned is called prior to FinishedSpawning for PlayerControllers and actors spawned with bDeferConstruction set to true

UE - Gameplay - Oct 12, 2017

When a PlayerController or any actor with bDeferConstruction set to true is spawned, OnActorSpawned.Broadcast is called prior to FinishSpawning which can cause issues as some components may not be i ...

Colon in UPROPERTY category invalidates iterative build

UE - Foundation - Core - Cooker - Jan 13, 2017

The presence of a colon ':' character in the category string of a UPROPERTY will cause iterative cooking to generate the following error:Found unparsable ini setting Windows.EditorPerProjectUserSett ...

Saving Level changes the Rotation of actors with parent-child relationships

UE - Gameplay - Components - Nov 14, 2019

According to the licensee report, UnrealMath.cpp (588) constfloat SINGULARITY_THRESHOLD = 0.4999995f; It seems that this can be avoided by changing the above value. However, changing SINGU ...

[AI] Failed check in UMassSpawnerSubsystem::DestroyEntities due to EntityManager still procesing

UE - Engine Scaling - Mass - Sep 7, 2025

It crashed when unspawning an AI which will destroy its entity. Inside DestroyEntities "IsProcessing" is true, but when it breaks into the debugger, "ProcessingScopeCount" is 0 (so IsProcessing shou ...

Dynamic Light placed inside of a Dynamic Static Mesh doesn't pass through the geometry

UE - Graphics Features - Jun 2, 2017

Dynamic Light placed inside of a Dynamic Static Mesh doesn't pass through the geometry. The static mesh is not double-sided. User Description: It appears that in Unreal 4.16 one loses the ability ...

Toggling visibility of Sublevels on a server can cause a disconnect if Dynamic Actors exist in the sublevels.

UE - Networking - Aug 17, 2018

The PackageMap / NetGuidCache appear to get into a bad state on Clients if the Server toggles level visibility of a sublevel. This can affect currently connected clients, as well as clients that jo ...

Request for 'Switch on Int' nodes to throw a warning or auto refresh if an execute pin is removed

UE - Gameplay - Blueprint - Nov 17, 2016

Request for 'Switch on Int' nodes to throw a warning or auto refresh if an execute pin is removed. For example: If the 0 pin is deleted, users may not realize the pins will reset back to (0,1,2,3,e ...

Editing and committing changes to a PackedLevelActor Blueprint results in a crash

UE - World Creation - Worldbuilding Tools - Level Instances - Apr 5, 2022

Repro Ratio: 3/3 Regression was tested in //UE5/Release-5.0-EarlyAccess CL-16682836 since this is a new feature of UE5.  The issue did happen ...

Sequencer crashes when scrubbing characters with sub-anim instances and montage slots

OLD - Anim - Oct 2, 2019

I saw a following assertion. Assertion failed: (AdditivePoses.Num() > 0) || (NonAdditivePoses.Num() > 0) [Link Removed] [Line: 1381] This is my quick fix// code placeholder void FAnimInstance ...

When r.SSR.Stencil is enabled, there is wrong logic observed.

UE - Rendering - Graphics Features - Dec 19, 2025

When r.SSR.Stencil is enabled, the areas with high roughnesss are not discarded and Unlit materials are incorrectly handled. See the linked EPS case (Additional Info URL) for a full explanation of ...