Unreal Engine Issues

UE 5.4 - Specular/reflection disappears above 4096 resolution render

After a viewport is more than 4096 pixels wide, Lumen's specular reflections buffer cuts its width off at 4096 pixels. It appears that the affected buffer is "Lumen.Reflections.ResolvedSpecularIndi ...

TOptional value changes in parent BP don't propagate to loaded child BPs

Context TOptional<T> is a wrapping struct around a type, that lets the property have an set and unset state, in addition to the property's value when set. It is editor exposed: designers can open b ...

Actor corruption due to Hierarchy broken after load

We recently hit a situation where some actors would suddenly teleport across the map when they were modified in the editor. We figured out that the AttachParent of some actors got reset on editor l ...

Recompiling blueprint actor in hidden sublevel, after reloading main level, detaches all its child actors

Reproduced 3/3 times, issue also occurs in //UE5/Release-5.0 - CL 20979098 Binary. Confirmed NOT a Regression. The repro steps are very specific for this; the core issue being that once the top lev ...

Custom node not working with material attributes

Using Material Attributes as an input to a Custom Expression causes the HLSL Translator to create multiple CustomExpression# functions, for each used member of the Material Attributes, rather than u ...

Vray Material nodes are disconnected after saved if closing and re opening Unreal

Editor crash when trying to launch on an Android target device from a Mac native platform

The one time it did not instantly crash after pressing the Launch button, I had to Kill -9 <PID> UE4Editor because it was using 129% of my CPU for 50 minutes. ...

UEditorEngine::OnAllPIEInstancesStarted() called prematurely, multiple times, while PIE clients are starting

Context UEditorEngine::OnAllPIEInstancesStarted() is a virtual function that gets called when launching Play-in-Editor. It can be overridden if the game project chooses to introduce a subclass of U ...

Distance Field Shadows do not work with Nanite meshes

Nanite meshes only cast virtual shadow maps and do not cast any distance field shadows, regardless of the distance of the shadow casting mesh to the camera. ...

Lyra - attribute sets of characters placed on world partition boundaries break in PIE

When placing an instance of ALyraCharacterWithAbilities on the map on the boundary between world partition cells, it fails to take damage in PIE. The expected attribute sets (HealthSet and CombatSet ...