Child Actor components on Clients use the incorrect default values for variables that are not being replicated

UE - Gameplay - Blueprint - Aug 28, 2018

When a Child Actor's class is replicated but the individual variables are not, the individual variables will use the default of the original BP class instead of the defaults that were set in the Chi ...

Missing Service Node warning when opening project

UE - AI - Sep 24, 2018

Services in the Behavior Tree sometimes don't work when the project is first loaded. The Behavior Tree will print a "missing service node" warning and the BT will remain inactive. This was reported ...

EarlyZPassOnlyMateriaMasking Makes Masked Materials on Particles Flicker When Close to the Camera

UE - Niagara - Oct 12, 2018

When "r.EarlyZPassOnlyMaskedMaterials" is enabled, masked materials used with particles will flicker when close to the camera. Found in 4.17 CL# 3658906, 4.18 CL# 3832480, 4.19 CL 4033788, 4.20 CL# ...

Confusing build error message provided when semi-colon is not added after a forward declaration in an Interface header file

UE - Foundation - Cpp Tools - UnrealHeaderTool - Feb 15, 2019

If a forward declaration of a class is made in the header file for an Interface class, and no semi-colon is included at the end of the forward declaration line, the build will fail with a confusing ...

GetTeamAttitudeTowards is called before AI Controller can spawn and gets a null value

UE - AI - May 6, 2019

Licensee is experiencing an issue where GetTeamAttitude is being called before the AI Controller's Construction event. This results in the warning "GetTeamAttitudeTowards - Pawn is null!" being outp ...

Nvidia Graphics Drivers cause editor menus to flicker and disappear after using the editor for an extended period of time

UE - Graphics Features - Apr 16, 2021

This issue seems to be occurring on a variety of Nvidia cards. So far, I haven't seen any indication that it is affecting AMD graphics cards. The majority of the reports have indicating that the pro ...

Editor 'Build All Levels' discards Volumetrics Lightmaps in persistent level

UE - Graphics Features - May 14, 2025

Building the level or lightmaps can clear the volumetric lightmap. In 5.5, this requires you to perform a full build, or a lighting only build with a BSP brush in the scene. In 5.6, all level build ...

Static code functions cause associated blueprints to not compile after a hot reload

UE - Foundation - Cpp Tools - Hot Reload - Oct 14, 2016

If a function inside a BlueprintFunctionLibrary class is declared as static, instances of the function node inside blueprints cause the blueprint to not save after a hot reload. This does not affec ...

Second Animation Sample added to AimOffset or Blendspace swaps with the first sample

OLD - Anim - Oct 3, 2016

Second Animation Sample added to AimOffset or Blendspace swaps with the first sample Note: After adding a 3rd sample, they switch back to the correct position. Regression: Sort of. In previous ...

Subclass disappears from class variable drop-down on re-open

UE - Gameplay - Blueprint - Mar 13, 2017

Subclass disappears from class variable drop-down upon reopening the project. There is a workaround for the issue but it is strange in nature. Opening the level blueprint and adding the node in scre ...