Inside a BP Interface, changing a Function output to an input will cause a compile error in the reference bp

UE - Gameplay - Blueprint - Apr 6, 2015

Inside a BP Interface, changing a Function output to an input will cause a compile error in the reference bp. [Error] "Graph named 'NewFunction_0' already exists in 'bpActor'. Another one cannot be ...

Calling a native interface function implemented by a non-nativized Blueprint asset from a nativized Blueprint asset will silently fail at runtime.

UE - Gameplay - Blueprint - Apr 29, 2020

In the sample project we have a Widget Blueprint asset (SomeWidget) that implements a native interface (PrintSomethingInterface.h). However, in the DefaultEditor.ini file, we've also excluded all Wi ...

In BP/Python Editor Utilities, function SetEditorProperty() unexpectedly fails for Actor Reference Properties on External Actors.

UE - World Creation - Worldbuilding Tools - May 19, 2024

As part of the Python and Editor Scripting Tools, it is possible to programmatically set variables in actor instances of the current level just like when using the Details Panel in the Level Editor. ...

'prefix parameter names' checkbox in a material function's settings does nothing.

UE - Rendering Architecture - Materials - Nov 14, 2024

Prefix Parameter Names checkbox does not work as expected, and the Group names are unmodified. The value "UMaterialFunction::bPrefixParameterNames" does not appear to be used anywhere in the Engine ...

Local Vector variables in functions do not save the Y and Z values

UE - Gameplay - Blueprint - Mar 12, 2015

Local Vector variables in functions do not save the Y and Z values. Possibly connected: after entering the X value, pressing Tab does not move to the Y value. Tabbing from there works as expected. ...

Wireframe persists Switching from 'Quad Overdraw' to 'Stationary Light Overlap' Visualizers

Tools - Aug 22, 2016

When switching from 'Quad Overdraw' to 'Stationary Light Overlap' in the Optimizations view mode visualizers, the wireframe generated in the overdraw visualizer persists into the overlap visualizer. ...

Dynamic light settings in Persona viewport cause edges to appear hardened

UE - Gameplay - Oct 11, 2016

Dynamic light settings in Persona viewport cause edges to appear hardened. See attached image, but also images in the Answerhub post. ...

Rect Light not rendered correctly when using Virtual Texture as source texture

UE - Graphics Features - Aug 14, 2025

Licensees have reported that this issue occurs when rendering from the command line: Rectangular lights with virtual textures do not render when you run the "Render (Remote)" button in the Editor, a ...

Compiling after copy/pasting Event Tick with references into function crashes editor

UE - Gameplay - Blueprint - Aug 29, 2016

When pasting nodes with references to an event tick into a function then compiling the editor will crash. Regression from 4.12.5 Binary CL-3039270 Edit - TravisL: I was able to repro this crash o ...

Indirect lighting cache generates points inside interpenetrating static meshes

UE - Graphics Features - Jun 10, 2015

Seems to be an issue with the indirect lighting cache where if you have interpenetrating static meshes (for example static mesh rocks that make up the ground), there are cases where the cache points ...