Niagara system loses source emitters when moving Engine from 4.22 or earlier to 4.23 or later.

UE - Niagara - Nov 29, 2019

The following code causes this behavior.// NiagaraSystem.cpp for (FNiagaraEmitterHandle& EmitterHandle : EmitterHandles) { EmitterHandle.ConditionalPostLoad(NiagaraVer); if (!EmitterHandl ...

Colors of Individual Lens Flare Tints Cannot be Changed in UE 4.18+

UE - Graphics Features - Jun 15, 2018

If you create a project in 4.17 and follow the Repro steps, you will be able to adjust the colors of individual lens flares. If you copy the 4.17 project into 4.18, 4.19, 4.20 Preview, or 4.21 the f ...

Split Struct pins cause errors when a project is converted to 4.17

UE - Gameplay - Aug 11, 2017

Split Struct pins cause errors when a project is converted to 4.17. You are still unable to split struct pins even if a new variable is created for the struct. Only adding a new variable to the st ...

4.6 Delegate error in Blueprints

UE - Gameplay - Blueprint - Dec 12, 2014

When looking into the bd_hud_scoring and bd_rules_maze blueprints in the users project (Provided below), there are nodes that are throwing errors. If you press compile, the errors go away and the co ...

World Delta seconds appears to Cause a miss calculation (regression 4.12.3 -> 4.12.4)

UE - Gameplay - Jul 1, 2016

If the user uses world delta seconds in a calculation there appears to be some incorrect values. Note there is also a users project attached if you would like to look at that example. ...

4.23 UpdateGrass took twice time than 4.22

UE - World Creation - Worldbuilding Tools - Foliage - Sep 12, 2019

Blueprint processing is heavy in PIE since 4.26

UE - Gameplay - Blueprint - Feb 17, 2021

As the attached image shows, there is no problem in 4.25.4, and the process is noticeably slower in 4.26.1. Also, there is no problem in Standalone. The problem occurs only in PIE. ...

Sound Cues with Attenuation 'Override' Nodes break when Upgrading project to 4.11

UE - Audio - Apr 5, 2016

When upgrading a project to 4.11, Sound Cues placed in the level with the 'Attenuation' override node no longer playback as expected. This issue was a bit weird when testing because the user report ...

Physics Constraint angular visualization are missing in 4.11

UE - Simulation - Physics - Apr 14, 2016

Physics Constraint angular visualization are missing in 4.11 This is a regression User Description: Since 4.11 angular constraints of the physics constant are not shown in the viewport. In 4.10 ...

Crash opening Child/Grandchild Blueprint after updating to 4.18

UE - Gameplay - Blueprint - Nov 29, 2017

From this UDN: https://answers.unrealengine.com/questions/718928/4180-editor-crash-while-opening-child-blueprint.html Crash occurs when opening child (or in the repro case, grandchild) blueprints a ...