Deferring Blueprint CDO construction at load time is leading to some data loss.

UE - Gameplay - Blueprint - Jan 27, 2023

Various licensees are reporting data loss on load due to the change that was made for [Link Removed] in which we now defer Blueprint CDO construction on load until the finalization phase. This issu ...

Sequencer: Camera Lock Breaks After Closing Sequencer and Re-entering PIE

UE - Anim - Sequencer - Oct 9, 2025

Viewport camera lock in Sequencer fails to persist correctly after running PIE with Sequencer open, then closing Sequencer and running PIE again. The issue consistently reproduces using the attached ...

Crash on Mac when adding Convex Collision to a mesh converted from a brush

UE - Platform - Apple - Jun 6, 2017

This is one of the top Mac crashes occurring in 4.16. Caused by adding Auto Convex Collision to a mesh converted from a brush. Does not occur on Windows. User DescriptionsI was trying to add a conv ...

UKismetArrayLibrary::GenericArray_Shuffle is weighted to return some results more than others

UE - Gameplay - Aug 15, 2017

The implementation of UKismetArrayLibrary::GenericArray_Shuffle() will generate certain array shuffle results more often (up to three times as much) than others, rather than having a roughly equal c ...

[CrashReport] ULevel::GetWorldSettings() - UMaterialInstanceThumbnailRenderer::Draw

Tools - Aug 29, 2017

This is a common assertion that has occurred since at least 4.14 and affected nearly 100 users. The callstack is similar to [Link Removed], which was marked fixed for 4.14. User DescriptionsUndoi ...

Compile warning/error in the FUpdateCollisionResponseHelper destructor

UE - Simulation - Physics - Dec 15, 2017

It has been reported that when building with Visual Studio 2017 version 15.5.1, a warning/compile error is shown in BodyInstanceCustomization.cpp: warning C4287: '<': unsigned/negative constant mism ...

Skeletal Meshes have physics collisions lag

UE - Simulation - Physics - Oct 2, 2019

Skeletal mesh's physics collision lag behind the actual mesh. It didn't matter if there was just a root bone or multiple bones/constraints. This doesn't happen when using static meshes. The effect ...

Changing the name of a native component results in a blank details panel

UE - Gameplay - Components - May 7, 2021

Much like [Link Removed] (which I'm backing down on my by design claim), there is an issue where if you previously referenced a component that no longer exists, the correct instanced subobject is lo ...

Subsurface Scattering Checkerboard with SceneColourFormat 3 (High Scalability) leads to a visual artefact when temporal upscaling is in use

UE - Graphics Features - Sep 30, 2024

Primarily visible at very low internal resolutions (25-33%), the SSS checkerboard with an RGB scene colour format (r.SceneColorFormat 3) causes a double-image artefact both internally and on the sil ...

Descriptions for vis log shapes in the Rewind Debugger are misaligned

UE - AI - Debugging - Mar 25, 2025

When recording shape information, descriptions are offset from the shape. Licensee Message - I noticed that the capsule vis log description labels were not lining up after replaying the recording ...