Client PlayerState is null on joining online session

UE - Networking - Jul 31, 2015

APlayerController::ClientStartOnlineSession() checks PlayerState at the start of a game after loading a level. Due to time needed to load in, client player state may may return NULL ...

Always Relevant actor may replicate incorrect movement mode when the walkable floor becomes irrelevant

UE - Gameplay - Player Movement - Feb 26, 2024

When the character class is set to always relevant, if a client travels very far away from another character, such that the character is relevant but the component they're standing on is not (but al ...

Resetting MovieSceneObjectBindingID property can't update display

UE - Anim - Sequencer - Apr 19, 2024

When reset a MovieSceneObjectBindingID type property, the display of the property is not reset but keep the value before reset, until the property form is clicked. [Image Removed] ...

Renaming a Blackboard Key removes it's references in the Behavior Tree

UE - AI - Jan 27, 2015

Renaming a Blackboard Key removes it's references in the Behavior Tree ...

Parent component visibility in a child blueprint isn't reflected in a launched project.

UE - Gameplay - Blueprint - Mar 5, 2015

Parent component visibility in a child blueprint isn't reflected in a launched/packaged project. ...

Niagara - When Interpolated Spawning is disabled, the first frame of each particle unexpectedly does not take into account the Particle Update stage

UE - Niagara - Feb 28, 2025

Foreword: Even if the behavior described here is by design, it is rarely (if ever) expected or desired. This was discussed and agreed to be treated as a bug. Explanation below. When interpolated sp ...

Physics Constraints do not have the same values if they are part of an 'Always Loaded' level

UE - Gameplay - Dec 3, 2014

Physics Constraints do not have the same values if they are part of an 'Always Loaded' level. They will work correctly in the Persistent level and a level that is Streamed in. This becomes problem ...

Hidden enumerator variables can cause the enumerator to become broken with the Select node in blueprints

UE - Gameplay - Blueprint - May 26, 2015

If a user makes an enumerator in C++ and sets one of the variables to Hidden and doesn't make it the last variable of the enum, it will cause issues with the numbering of the enum when using the Sel ...

In Editor, Blueprint resources are not freed up when the Blueprint is closed

UE - Framework - Blueprint - Feb 16, 2024

It appears that the preview scene used to render thumbnails is not destroyed after a thumbnail is rendered, even after the blueprint editor is closed and GC is run. Also found in Release-5.4, CL: 31 ...

Internal Compiler error when calling a custom enum in a struct from a blueprint macro

UE - Gameplay - Blueprint - Aug 6, 2015

If a macro is referencing a custom enum within a struct and compiled after another output pin is removed, an internal compiler error will appear and the blueprint will not compile. ...