Reimporting of skeletal mesh results in a scrambled skeletal mesh

UE - Editor - Content Pipeline - Import and Export - Oct 17, 2025

When we reimport our skeletal meshes with updated FBXs, the resulting skeletal mesh is scrambled up. See Scrambled.jpg attached. This does not affect every single reimport but happens randomly. W ...

FDetailGroup::AddGroup does not correctly apply the default expansion state for DetailGroups

UE - Editor - Verse Class Editor - Feb 10, 2026

There is a bug affecting DetailGroups in the engine. When adding child DetailGroups to a parent DetailGroup, the expansion state does not behave as expected and ignores the flags intended to control ...

Creating Destructible with PhysXLabs and Fracture Tool in UE4 yield different results and same settings

UE - Simulation - Physics - Destruction - Feb 25, 2015

When creating fracturing a mesh in PhysXLabs vs UE4 fracture tool with both using Voronoi fracture and set to 25 chunks will give different results. The mesh (Attached below along with reference i ...

[CrashReport] UE4Editor_UnrealEd!UnFbx::FFbxImporter::RecursiveBuildSkeleton()

UE - Editor - Content Pipeline - Import and Export - Jul 30, 2015

This is a common crash affecting users. User DescriptionsJust import a Mesh of Fuse Source Context 624 void UnFbx::FFbxImporter::RecursiveBuildSkeleton(FbxNode* Link, TArray<FbxNode*>& Out ...

[CrashReport] UE4Editor_Sequencer!FSequencer::NotifyMovieSceneDataChanged()

UE - Anim - Sequencer - Jul 24, 2017

This is a common crash affecting users in 4.16 and into the 4.17 Preview. User Descriptionscopying-pasting curves in Sequencer Source Context 979 void FSequencer::NotifyMovieSceneDataCha ...

Cloth Rendering - Optimizations cause a one frame geometry stretch when off screen cloth is teleported back on screen.

UE - Simulation - Core - Aug 26, 2021

Render optimizations are causing the cloth render data to be updated one frame too late after an off screen cloth object has been teleported back on screen. The optimisation triggers itself after a ...

OnTextChanged not called for UEditableTextBox / UMultiLineEditableTextBox when text is set programmatically

UE - Editor - UI Systems - Sep 29, 2025

When calling SetText() on a UEditableTextBox or UMultiLineEditableTextBox, the OnTextChanged delegate is not triggered. This regression was first reported in UE 5.3 and acknowledged previously in UD ...

Copying a destructible mesh in the viewport loses reference to assigned mesh in the details panel

UE - Simulation - Physics - Destruction - Nov 4, 2014

BRANCH: MAIN CHANGELIST: 2346079 PLATFORM: Windows DESCRIPTION: When copying a Destructible mesh in the viewport the Destructible Mesh component will not be shown for the copied mesh. The mesh can ...

Morph Targets flicker Randomly in Slave Mesh

OLD - Anim - Oct 1, 2015

When a mesh is slave to a master mesh, its morph targets will flicker when Played in Editor. This does not occure with the same assets in 4.8. This has been reported by at least two different use ...

FBatchedElements::Draw - OrthoZoomFactor can be reset to 1.0f if Line.bScreenSpace is ever false

UE - Graphics Features - Feb 20, 2017

A licensee has reported that the Draw function in BatchedElements.cpp can set the OrthoZoomFactor (not a local variable) to 1.0f if Line.bScreenSpace is ever found to be false. The line this can oc ...