Blueprint with Niagara System and Skeletal Mesh Components Automatically Updates Niagara System Skeletal Mesh

UE - Niagara - Apr 4, 2019

When adding a niagara system that reproduces a skeletal mesh and a skeletal mesh as components to a blueprint, the niagara system immediately updates its skeletal mesh to the most recently updated s ...

UClass::SparseClassDataStruct null at editor-time for child blueprints until compile

UE - Framework - Blueprint - May 29, 2024

Child blueprints of a blueprint of a native actor class with sparse data can have an incorrectly null SparseClassDataStruct value, and thus fail to initialzie their SparseClassData. This affects edi ...

Translucent materials in the PostMotionBlur pass can cause a flickering viewport artefact when using TAA

UE - Graphics Features - Feb 5, 2025

There appears to be a bug relating to rendering multiple windows that can trigger under unknown circumstances. It has been reported on rectangle lights in the forums and on PostMotionBlur materials ...

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 ...

After breaking a level instance without Actor Folders, moving its actors between folders of the world-partition map does not work correctly

UE - World Creation - Worldbuilding Tools - World Partition - Jan 29, 2024

If a standard level (without Actor Folders enabled) is added to a world-partition map (with Actor Folders enabled) as a Level Instance, and then that instance is "broken" so that its actors are inco ...

Crash when executing Rename Asset or Duplicate Asset and other functions in Scripted Actions

UE - Gameplay - Blueprint - Jan 8, 2019

In Scripted Actions, if you execute a function after using Rename Asset or Duplicate Asset, it will crash. If you do not execute the function it will not crash. ...

Compiling UObject blueprint causes Instanced variables of the blueprint type to show as "REINST" in other blueprints

UE - Gameplay - Blueprint - Oct 7, 2016

When a UObject blueprint is compiled, other blueprints with an Instanced variable of that type will show as REINST and will not recognize the original blueprint data. ...

HideCategories() property is not held when the editor is closed

UE - Gameplay - Blueprint - Mar 20, 2015

Setting a UCLASS() macro with the "HideCategories" property will updated after a hot reload but after closing /reopening the editor the hidden category will be visible again. ...

ios launch fail after upgrading to 4.7.1, provision not found, signing key not found

UE - Platform - Mobile - Mar 2, 2015

Customers that have never or have created an incorrect bundle identifier will fail to package for iphone. People who have wildcard provisions will work. ...

Changing variable type of event dispatcher results in permanent warning

UE - Gameplay - Blueprint Compiler - Aug 18, 2018

If you change the type of an event dispatcher variable (why is this a thing?!), then you will permanently have a warning of the form "No delegate property found for NewEventDispatcher_0" that will ...