Unable to save blueprint after Hot Reload that affects the class the blueprint is based on

UE - Gameplay - Blueprint - Sep 14, 2015

After hot reloading a project, if the class a blueprint is based off of was edited, the blueprint is unable to be saved due to being referenced in Engine/Transient. Project for Repro: [Link Removed ...

Can Ever Affect Navigation does not detect updates to collision settings at runtime

UE - AI - Jan 27, 2016

When a mesh has its collision updated during runtime the navigation around the mesh does not update. Workaround: If the mesh is set to simulate physics then updates to its collision will update nav ...

Map placed actor binding to another actor's Event Dispatcher (multicast delegate) results in duplicate bindings after blueprint recompile

UE - Framework - Blueprint - Apr 17, 2025

Context Blueprint actors placed on the map can bind to another actor's event. If an ActorB has a reference to ActorA, it can bind to an event dispatcher in A by creating an event node in ActorB's e ...

Translucent Materials no longer reflect light when using Forward Lighting variable

UE - Graphics Features - Jun 7, 2016

Translucent materials are no longer showing light reflections in scene when using r.forwardlighting 1 with lights. This is a regression from functionality in 4.11.2. This no longer works with 4.12 ...

Map Get Node Pins In Niagara Module Scripts Can't Search For Standard Data Types

UE - Niagara - Mar 16, 2020

This wasn't like this in 4.24 (see attached images). If you create a variable Engine.Owner.Position the search will find it however. Found in 4.25 Preview 2. Reproduced in 4.26 Main. ...

Niagara Scalability Crash When Processing Significance

UE - Niagara - Jun 4, 2025

Method FNiagaraScalabilityManager::ProcessSignificance() iterates on indices from Context.SignificanceIndices and uses them to access the State and ManagedComponents arrays. It can then decide to cr ...

Aligning comment boxes does not move the nodes within them

UE - Gameplay - Blueprint - Nov 13, 2015

Aligning comment boxes does not move the nodes within them. Reproduced in 4.10.0 binary and Main (CL# 2765781). Not a regression: Blueprint node alignment was not available prior to 4.10. ...

Investigate crash reported with 4.16 on Sony Xperia Z3 running Marshmallow

UE - Platform - Mobile - Jun 28, 2017

A user has reported a crash that is occurring on his Sony Xperia Z3, https://answers.unrealengine.com/questions/667998/4161-dev-build-app-crashes-on-start-unfortunately.html The user has attached ...

Teleport only affects static mesh of destructible meshes, collision remains at original location

UE - Simulation - Physics - Destruction - Sep 15, 2015

Teleporting a destructible mesh only transports the mesh of the object, the collision remains where it was originally located. Further, if the player runs into the collision, the static mesh will re ...

Xcode 26/16.4 Metal Toolchain generates metallib's that are not compatible with iOS 16

UE - Platform - Apple - Sep 23, 2025

Below is the error output from FirstPerson template as a C++ project: {+}../../../FirstPerson58CPP/Content/firstperson58cpp_sf_metal_es3_1_ios-metal_es3_1_ios.0.metallib, 5881486 bytes!2025-09-23 1 ...