Crash When Loading Cooked Material Assets in Editor Due to Shader Serialization

UE - Rendering Architecture - Shaders - Aug 27, 2025

In Unreal Engine 5.6+, the new shader serialization logic in FShaderMapResourceCode::Serialize does not correctly handle cooked assets that are loaded back into the editor (e.g., from a mounted .pak ...

TBaseBlendedCurve::ConvertToAdditive adds a curve track to an additive when the curve only exists in the base pose

UE - Anim - Runtime - May 29, 2023

When we create curves on additive animations, we are creating a curve based on whether the curve exists in either the base or additive pose.  This wouldn't be the expected behaviour for a user when ...

Materials with Subsurface Profile not affected by Opacity value

UE - Graphics Features - Oct 24, 2017

A material with Shading Model set to Subsurface Profile is no longer affected by Opacity value in 4.17, 4.18, and 4.19 (Main) but was previously working as intended in 4.16. This is a regression. ...

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 - FBX - 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 ...