Crash when removing native root component from code after creating a Blueprint class based on the native class.

UE - Gameplay - Blueprint - Jul 27, 2015

Crash occurs when removing the native root component from code and then attempting to reopen a Blueprint Class asset that was based on the native parent class. Seems like maybe the 'AttachParent' f ...

Blendspace Animation Lag for Morph Targets

OLD - Anim - Sep 11, 2015

Blendspace animations of morph targets play at a slightly but noticably different rate between the 4.8 and 4.9 version of the UE4. ...

bool variables set in code do not auto-update after a hot reload

UE - Gameplay - Blueprint - Apr 6, 2015

When a bool variable is defined in code, changing the default value of the variable does not update on a hot reload This is inconsistent with other variables types that update their current value w ...

Packaging fails after changing from Dynamic to Static Nav Mesh Runtime Generation

UE - AI - Feb 8, 2016

If you package with Runtime Generation set to Dynamic and then switch to Static and attempt to repackage, the packaging will fail with the following error message.[2016.02.08-16.18.14:511][217]MainF ...

When Allow Sequencer Edits Only is Enabled Some Properties Do Not Revert to Original Values

UE - Anim - Sequencer - Oct 23, 2017

Certain values for the PostProcessVolume do not revert back to original values after tracks are deleted from sequencer when in Allow Sequencer Edits Only mode ...

Hypotenuse node unexpectedly returns "-nan(ind)" instead of "0.0" if both values passed into the node are "0.0"

UE - Gameplay - Blueprint - Feb 1, 2019

The Hypotenuse Blueprint node currently returns a value of "-nan(ind)" if both values passed into the node are "0.0". This result is correct based on the code that the Hypotenuse node uses, but is n ...

[Spatialization] - When a sound starts playing while the listener in in the Binaural Radius, when they exit the sound stops playing

UE - Audio - Spatialization - Nov 18, 2021

If a sound starts playing while the listener is inside the binarual radius, the sound stops abruptly when they leave the radius. Does not occur if the listener starts in the binaural radius. Does no ...

Inherited UserWidgets can't create animations that bind to widgets on their parent's WidgetTree

UE - Editor - UI Systems - UMG - Nov 7, 2022

Animating an inherited widget from a child UserWidget class appears to work, but the bindings don't resolve properly and the animation is null at runtime. This workflow should either be supported, o ...

When a Niagara User Parameter is renamed, mesh bindings on Niagara Mesh Renderers are not updated, and the binding is silently broken

UE - Niagara - Mar 13, 2025

In Niagara, Mesh Renderers expose a "Meshes" array for selecting the meshes to be rendered. On each array entry, a property "Mesh Parameter Binding" is available and allows the user to override that ...

Find in Blueprints: Default values of TMap keys are not returned

UE - Framework - Blueprint Editor - Sep 3, 2025

Context Find-in-Blueprints can be used to search the current, or all, blueprints. If you enter a simple string, it would return nodes, pins, pin default values and default values for BP Variables ( ...