References to Data Assets that inherit from Blueprints may be broken during reinstancing

UE - Gameplay - Blueprint - Nov 30, 2020

It is possible to create new Data Asset instances in the editor that inherit from a blueprint-defined subclass of UDataAsset. This flow is not very well supported, and generally it is safer to just ...

[CrashReport] UE4Editor_CoreUObject!UObjectBase::IsValidLowLevelFast() [uobjectbase.cpp:294]

UE - Foundation - Core - Aug 22, 2017

This is a common crash in the 4.16 and 4.17 releases. User DescriptionsWriting a custom component in C++. Hotcompiled it through VS2017. Had the BP editor open with a class derived from that compo ...

UBT Output log encoding does not match if non-ASCII characters are in the UBT output

UE - Foundation - Cpp Tools - UnrealBuildTool - Nov 21, 2019

UBT Output log encoding does not match if non-ASCII characters are in the UBT output. Before UE4.23, UBT output encoding problems only exist in the editor "Compiler Log" under Developer Tools, and i ...

[CrashReport] Mac crash in FThreadStats::FThreadStats()

UE - Platform - Apple - Jan 3, 2017

This is a commonly reported crash from Mac users in the community. The repro steps are currently unknown, and appear to be varied based on user information below.zoomed out quickly while in a bluepr ...

Additive Animation does not work as intended when Ref Frame Index is more than zero

UE - Anim - Runtime - Dec 19, 2023

In some conditions, additive animation shows different/wrong behavior on Standalone Game and packaged game, from the other PIE. Watch the attached video. [Link Removed] The key points to reproduce ...

Undo/Redo can cause the gizmo to desync from a leaf-selected component

UE - Editor - Workflow Systems - Oct 18, 2021

This is a regression from 4.27. This is happening because of the change to typed elements. UEditorEngine::PostUndo, when combined with the typed element changes causes the selection set to reorder ...

MaterialX texture imports won't import files with the same name

UE - Editor - Content Pipeline - Import and Export - Apr 2, 2025

Hello! When importing .mtlx files that contain textures with the same name (but different filepaths), only the first texture is imported. This seems to be due to the function CreateTextureNode() i ...

[CrashReport] UE4Editor_ClothingSystemRuntimeInterface!UClothingSimulationFactory::CreateSimulation()

UE - Simulation - Physics - Character - Jun 27, 2017

This is a common crash in the 4.16 release. Users have not provided descriptions so additional information is not currently available. Source Context 28 // Any clothing simulation factory s ...

Vertex Color Information Lost on Editor Restart

Tools - Apr 19, 2018

This is a regression. In 4.19 and Main (CL 4008322), vertex color information does not save properly and data is lost when editor is reopened. Creating project from scratch instead of copying over f ...

[CrashReport] UE4Editor_UnrealEd!UEditorEngine::FinishDestroy() [editorengine.cpp:857]

Tools - Mar 28, 2016

Error message: Assertion failed: PlayWorld == NULL [Link Removed] [Line: 854] Source Context:842 void UEditorEngine::BroadcastObjectReimported(UObject* InObject) 843 { 844 ...