AI Perception UnregisterSource Sense == nullptr does not affect pending adds

UE - AI - Perception - Jun 15, 2022

UAIPerceptionSystem::UnregisterSource according to its documentation should treat Sense == null as targeting all sources, but the code for removing pending sources does not treat Sense == null as th ...

Hide Categories in a blueprint will not affect categories in inline components

UE - Editor - Workflow Systems - Oct 12, 2022

This occurs because ObjectPropertyNode.h will only check if a category is hidden for it and its subclasses. It should also be checking the parent's categories if it's an edit inline component. ...

WP level instance runtime settings affect streaming generation

UE - World Creation - Worldbuilding Tools - World Partition - Nov 16, 2023

If a level instance uses different runtime settings then it can override the main WP's runtime settings with UWorldPartitionRuntimeSpatialHash::ApplyCVars Runtime settings:GRuntimeSpatialHashUseA ...

Level Streaming - Always Loaded sublevel affected by streaming volumes

UE - World Creation - Worldbuilding Tools - Mar 19, 2024

The docs mention: "When a streaming Level is set to Always Loaded, it is loaded together with the persistent Level. It also becomes visible at the same time as the persistent Level. It ignores strea ...

Shadow doesn't update for a moving nanite mesh (fixed in 5.4)

UE - Graphics Features - Shadows - Mar 25, 2024

When a nanite mesh moves, the shadow does not. ...

[CrashReport] Access violation - FLandscapeEditDataInterface::SetAlphaData()

UE - LD & Modeling - Terrain - Landscape - Jul 19, 2017

This is a common crash affecting users in 4.15 and 4.16. This callstack was previously linked to [Link Removed], but that had a specific repro case that was fixed in 4.14. Users are not providing ...

Using Tortoise SVN causes the engine's source control to be inconsistent

Tools - Jun 16, 2015

If a user decides to use Tortoise SVN, the error messages given for needing to have things checked out is inconsistent. If there is a blueprint which references another blueprint, and the reference ...

ChaosWheeledVehicleMovementComponent is breaking the const CDO contract and changes to the instances are being applied to the CDO

UE - Simulation - Physics - Apr 28, 2025

As described by the licensee, the const CDO contract is being broken on ChaosWheeledVehicleMovementComponent. The issue the licensee is facing is that by spawning cars with different configurations, ...

Touch End events do not fire if asset is moved from under touch location

UE - Gameplay - May 19, 2016

Touch End does not get fired if actor is not under cursor when released. Regression (no) issue (does) occur in 4.10.4 ...

FBX material IDs from 3DS Max are reordered in automatic LOD generation

Tools - Sep 12, 2018

This appears to be a UE4 bug in the way it handles the importing of FBX Material IDs from 3DS Max exports.Max uses set Mat IDs to organize multiple materials on a single object.UE4 correctly handles t ...