Actor Component properties can become "linked" across multiple Blueprints after a hot reload

UE - Gameplay - Components - Dec 3, 2018

If code in an Actor Component class is changed (eg. a new UPROPERTY is added) and a hot reload is performed to implement the changes, the properties in the component can become linked across any Blu ...

Ragdoll replication on server side is not replicated correctly on client

UE - Networking - Dec 2, 2014

Ragdoll replication on server side is not replicated correctly on client. The client will see the server players ragdoll dissappear and reappear at the 0,0,0 origin point. AnswerHub Posts: https: ...

Properties not serialized when moving actor/component depending on unrelated specifiers

UE - Gameplay - Blueprint - Sep 25, 2023

When an actor is moved on the level editor viewport, it is reconstructed along with its components, which at first makes their properties reset to their default state. Thankfully, this does not happ ...

Set Members in Struct node doesn't work if the Struct is contained within an Array

UE - Gameplay - Blueprint - Dec 9, 2014

Set Members in Struct node doesn't work if the Struct is contained within an Array. ...

Control Rig settings are not retained between editor sessions or carried into deployed game

UE - Anim - Rigging - Control Rig - Jun 10, 2020

Control Rig settings are not retained between editor sessions or carried into deployed game ...

Add Submix Effect Blueprint Does Not Have Any Effect

UE - Audio - Dec 11, 2020

Adding a second effect to the Submix Effect Chain on a Submix works as expected, but when trying to add a Submix Effect via Blueprint, there is no effect.  This also applies to "Add Master Submix Ef ...

Get Mouse Position Blueprint node returns different values outside of viewport depending on whether it was called from Event Tick, or within an Actor function

UE - Gameplay - Nov 15, 2018

There seems to be a discrepancy between the output of Get Mouse Position node depending on whether the node is inside an Actor function or called from Event Tick. If the node is present inside a fun ...

Race condition in full builds of UE4 engine source

UE - Foundation - Cpp Tools - UnrealBuildTool - Sep 26, 2019

This is a race condition caused by how "Clean.bat", a batch file used during rebuilds, tries to manually rebuild the UnrealBuildTool project when it runs. This causes a spam of UnrealBuildTool build ...

Editor crashes on Mac when launching with the command -MacExplicitRenderer=0

UE - Graphics Features - Jan 19, 2017

Trying to launch the editor with the command -MacExplicitRenderer=0 causes a crash. At the time of the crash, the following line appears in the log:LogMac:Error: appError called: Assertion failed: A ...

Create Session does not work in a packaged game from any project that has used C++

UE - Networking - Dec 28, 2015

After adding C++ to a content-only project, Create Session no longer works in a packaged game. The following warning appears in the log: LogScript:Warning: CreateSession - Invalid or uninitialized ...