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 ...

[CrashReport] UE4Editor_Core!FFileHandleWindows::Seek() [windowsplatformfile.cpp:501]

UE - Foundation - Core - Aug 29, 2017

This is common crash coming out of the 4.17 and 4.18 releases. The callstack is similar to an old unresolved import crash: [Link Removed] User Descriptionsrebuilding lightbuilding lighting from a d ...

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 ...

[CrashReport] UE4Editor_DerivedDataCache!TArray<unsigned char,FDefaultAllocator>::ResizeGrow()

UE - Graphics Features - Sep 20, 2017

This is a somewhat common crash occurring in 4.17. Users have not provided any description of their actions when the crash occurred. Source Context 165 if (GWarn) 166 { 167 ...

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 ...

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 ...

Render target size mistmatch in ShaderDrawDebug

UE - Graphics Features - Jun 9, 2020

We found a d3d debug validation assert in RDG_EVENT_NAME("ShaderDrawDebug"), with the full DLSS integration. It however also reproduces in  (4.25.1-release, dev-rendering and the plugin branch with ...

Wrong density calculation in UBodySetup::CalculateMass

UE - Simulation - Core - Sep 29, 2025

Wrong density calculation in UBodySetup::CalculateMass. The licensee has provided the following analysis and suggested fix: In UBodySetup::CalculateMass, the following code is present: // physical ...

[CrashReport] UE4Editor_Core!FName::GetDisplayNameEntry() [unrealnames.cpp:894]

UE - Foundation - Core - Aug 14, 2017

This is a trending crash coming out of the 4.17.0 release. The same callstack also occurred during the 4.11 release, but otherwise hasn't had an occurrence until now. Users have not provided any de ...

[CrashReport] FLandscapeEditorCustomNodeBuilder_TargetLayers::OnTargetLayerDeleteClicked()

UE - LD & Modeling - Terrain - Landscape - Oct 5, 2017

This is a somewhat common Landscape crash occurring throughout the 4.17 release. User Descriptions1) rename landscape layer, 2) delete layer in landscape tool Source Context 1307 FReply FL ...