It's possible to create a locked state on a rigidbody by creating a TransientField that will keep the rigdbody Sleeping even after it leaves the Field's area of influence

UE - Simulation - Visual - Sep 5, 2024

The licensee found a way to lock the state of a rigidbody as PBDRigid->ObjectState() == EObjectStateType::Sleeping by subjecting it to a particular transient field composed of a RadialFalloff and a ...

Arrays in UMaterialEditorInstanceConstant are not updated

UE - Rendering Architecture - Materials - Jun 13, 2025

Any UPROPERTY TArray added to UMaterialEditorInstanceConstant will not cause UI updates when elements are added or removed. This is caused by the custom validator created in FMaterialInstanceEditor ...

Switching modular control rig to FK mode breaks pose of controls that have been baked to rig

UE - Anim - Rigging - Control Rig - Sep 14, 2025

From the licensee:We have built a modular Control Rig in Unreal 5.6, and while IK to FK matching works correctly inthe rig, but we are facing an issue when applying mocap animation to the characters ...

Extending Montage Segment length causes length to reset to default in new Editor Session

OLD - Anim - Jan 4, 2016

Licensee is encountering an issue where they would like a segment of a montage to end and hold the last frame for the remainder of the segment length. He is doing this by adjusting the End Time und ...

After changing Slot Name field, Slot node does not update until you re-open the AnimBP

OLD - Anim - Jun 9, 2015

After changing the Slot Name field, the Slot node does not update with the new name until you close and re-open the Animation Blueprint ...

Live: Crash when opening a blueprint who's component was edited in VS

UE - Gameplay - Blueprint - Oct 31, 2014

Added functionality to a blueprint component through code and built the project in VS. After a hot reload, I saved the blueprint and closed the editor. Reopening the editor and the blueprint cause ...

Sweep on Set Actor Location is ignored for all components that aren't the Blueprint's root

UE - Gameplay - May 28, 2015

Sweep on Set Actor Location is ignored for all components that aren't the Blueprint's root. Reproduced in 4.7.6 and Main (//depot/UE4/Promotable-CL-2568226) ...

Stat FPS will freeze a project when packaged for shipping

UE - Foundation - Core - Mar 31, 2015

If you have an Execute Console Command node in your level blueprint with a pressed key executable node, The project will freeze if packaged for shipping when 'Stat FPS' in in the Command box. Test ...

Root Motion (RMFE) - Blend with cached pose causes inaccurate root motion

UE - Anim - Gameplay - May 28, 2015

With Root Motion From Everything enabled, a Blend node gives different results when feeding it Animation Sequences directly or when first using a Cached Pose. *Simple test project attached Two sce ...

The Child Actor Component cannot be selected in the Blueprint Editor Viewport

UE - Gameplay - Jun 8, 2015

The Child Actor Component cannot be selected in the Blueprint Editor Viewport. Selecting the Child Actor Component in the Components tab is the only way to select the component. Reproduced in 4.7.6 ...