Reference to control rig can be lost on actors with multiple skeletal mesh components

UE - Anim - Rigging - Control Rig - Apr 4, 2023

In the attached project, when we initially add a control rig track for the actor with multiple skeletal mesh components, we add the control rig for the correct component because FControlRigParameter ...

FUniqueNetIdRepl::NetSerialize() crashes when embedded in a TArray() of structs.

UE - Networking - Jun 29, 2020

Calling the NetSerialize() function of FUniqueNetIdRepl from a custom NetSerialize() causes a crash. This only seems to occur when the struct is part of an array RPC parameter. ...

Changing blueprint default values inside arrays only updates loaded child blueprints

UE - CoreTech - 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 ...

Physics Asset primitives are being created with the default Name as None instead of BoneName_PrimitiveType

UE - Editor - Content Pipeline - Import and Export - Oct 27, 2024

When creating Physics Assets, either by automatic creation upon import, creation from skeletal meshes already in the project, or when we press Generate All Bodies (bottom right of a opened Physics A ...

Cannot select child anim BPs for use in linked anim layers

UE - Anim - Runtime - Jul 15, 2021

From UDN: [Link Removed] Unable to set a Child ABP with inherited interface to a Linked Animation Layer Instance Class. I have a ABP_Biped which is our main ABP. I have the locomotion (idle+straf ...

[CrashReport] UE4Editor-UnrealEd.dylib!TBaseUObjectMethodDelegateInstance<false, UEditorEngine, TTypeWrapper<void> ()>::Execute()

UE - Platform - Apple - Nov 10, 2017

This is a longstanding but low frequency Mac crash. Users have not provided any descriptions of their actions when the crash occurred. Callstack from Log[2017.10.26-22.22.57:828][183]LogSavePackag ...

Instanced Static Meshes ignore max World Position Offset Displacement for bounds after UpdateInstanceTransform is called

UE - Graphics Features - Jun 18, 2025

When an Instanced Static Mesh Component (ISMC) uses a material with a non-zero Max World Position Offset Displacement, the bounds are correctly expanded at initialization. However, after calling Upd ...

When a Niagara System has SimTarget set to GPUCompute Sim, CameraQuery is only returning data from the Player0 camera, ignoring the PlayerControllerIndex.

UE - Niagara - Nov 8, 2024

When a Niagara System has SimTarget set to GPUCompute Sim, CameraQuery is only returning data from the Player0 camera, regardless of PlayerControllerIndex. The expected behavior would be to have the ...

AbilityTask_PlayMontage will 'zombie' if Interrupted during BlendOut

UE - Gameplay - Gameplay Ability System - Apr 14, 2023

User reports: I've noticed a bug with PlayMontageAndWait There are 4 possible triggers when a Montage completes:OnCompletedOnBlendOutOnInterruptedOnCancelled Once OnBlendout has been triggere ...

Overriding blueprint function first in grandchild class then in child class renames grandchild function

UE - Gameplay - Blueprint - Nov 28, 2017

If you have a blueprint A with a child blueprint B, and child of the child blueprint C, overriding a function with a return parameter originally declared in blueprint A in the blueprint C, and then ...