Editor crashes on start up after updating to 5.0 - Assertion failed: (TTraits::WithIdentical || TTraits::WithIdenticalViaEquality) [File:E:\UnrealEngine\UE_RelTestA\Engine\Source\Runtime\CoreUObject\Public\UObject\Class.h] [Line: 1476]

Quixel - Apr 6, 2022

User's are reporting that after updating to 5.0 the editor crashes on start up. This happens when converting an old project, creating a new project, or attempting to open a project. Some are reporti ...

Copying collapsed graph with a node with a custom Exec pin results in duplicate pin name

UE - Framework - Blueprint Editor - Aug 17, 2022

When duplicating a collapsed blueprint graph which has a node with a custom Exec pin, this results in blueprint compilation error that a duplicate named pin is found. Duplicated exec pins aren't ass ...

FAnimUpdateRateParameters::GetInterpolationAlpha appears to be returning an invalid value for TrailMode

UE - Runtime - Animation - Aug 5, 2023

It appears that  FAnimUpdateRateParameters::GetInterpolationAlpha is not returning a sensible value when running in TrailMode.  Currently the only variable in the calculation is EvaluationRate which ...

FInstancedStruct member uproperties are not cached when "Generate Optimized Blueprint Component Data" is enabled

UE - Framework - Blueprint - Nov 18, 2025

A licensee has encountered an issue where their FInstancedStruct isn't being gathered into CachedPropertyData when "Generate Optimized Blueprint Component Data" is enabled. The changes in [Link Remo ...

Instanced Actors: Moving element in editor is not undoable

UE - Engine Scaling - Mass - May 30, 2026

Context Instanced Actors can be moved by unchecking Lock Instance Locations on an IAM, and double-clicking into the actor → comp → instance to select an instance. Problem Moving an IA via the giz ...

Crash when creating new projects or converting copies of old ones in Japanese

UE - Editor - UI Systems - Slate - Dec 4, 2014

There's a crash in FCharacterList::GetKerning() when using the editor in Japanese that is apparently fixed in one of these three changelists: CL# 2370014, 2370050, and 2370040 But they were not ...

Blueprint 'Select' node: nodes connect to all input pins are evaluated while only one input is needed

UE - Gameplay - Blueprint - Aug 15, 2015

Originally marked Won't Fix in 2017. Issue reopened on May 1, 2024. All inputs of a Select blueprint node are evaluated, even though in the end only one value is selected. This is wasteful work. ...

FBX Scene Importer sets actors in Blueprint to movable when reimporting

UE - Editor - Content Pipeline - Import and Export - Nov 28, 2016

When using the FBX Scene Import into Level with default settings so that the actors in the BP import as static, if you reimport them they will then be set to Movable in the BP. This is not a regre ...

Mesh reduction crash with asset imported using FBX Scene Importer

UE - Graphics Features - Nov 30, 2016

The editor will crash when using Mesh Reduction on an asset imported using the FBX Scene Import options. This same asset will not crash the editor if it has been imported using the normal Import opt ...

Replace Reference feature is not replacing textures with new selected texture

Tools - Jan 4, 2017

Workaround:Open M_TableRound, move a node. Save the MaterialReopening the project seems to fix the issue Replacing the reference of the deleted table texture is rendering default material. Note T ...