References to Data Assets that inherit from Blueprints may be broken during reinstancing

UE - Gameplay - Blueprint - Nov 30, 2020

It is possible to create new Data Asset instances in the editor that inherit from a blueprint-defined subclass of UDataAsset. This flow is not very well supported, and generally it is safer to just ...

Users can't change flags on asset entries in PSD when the asset was added via a Branch In notify

UE - Anim - Gameplay - Mar 19, 2025

Assets added to a PSD via a Branch In notify can't have their flags changed within the database. When the flags (like mirror, disable, etc) are changed, they revert back to the original value when ...

AssetRegistry has poor performance when a large map is resaved: Directory IO

UE - Foundation - Data Pipeline - Cooker - Mar 10, 2025

IO cost of directory scans is one of the costs present in the AssetRegistry when a large map is resaved. Maps can have external actors which all have to be rescanned and reported to the map for incl ...

ForEachLoop does not save structure changes in the loop body

UE - Gameplay - Blueprint - Feb 2, 2015

If a ForEachLoop node is used to cycle through an Array of Structures, using the Array Element output of the Loop node to set the members of the structure does not save the changed values. Workarou ...

Editing InlineEditConditionToggle variable value causes editor to crash

Tools - Oct 7, 2016

Editing property with InlineEditConditionToggle meta specifier causes the editor to crash. Workaround: Calling Super::PostEditChangeProperty after property changing code prevents crash from occurri ...

Blueprint classes are listed in Object pickers, but will not work as expected

UE - Gameplay - Blueprint - Jul 28, 2020

Because of the way blueprints are implemented, the "Blueprint Class" asset actually points to the editor-only UBlueprint object. Because of this, all blueprint classes will show up as options for ge ...

Adding new elements to an array in code does not update in a class based blueprint on compile

UE - Gameplay - Blueprint - May 5, 2015

When adding elements to an array inside a code class, blueprint instances of the class do not have their array updated after a hot reload. ...

AR Core - Apps with Candidate image result in black screen on first launch

UE - Platform - XR - Jan 20, 2020

On first launch of an AR app with Android the camera passthrough will render black. This also happens if an app is minimized and re-opened. This will not repro if there is no candidate image assign ...

UDataLayerManager::Initialize perf issue in Editor build

In editor, WorldDataLayers acceleration table used to map DL Names to DL instances is not created. The main reason was to avoid to handle all the case where it would need to be updated. When UDataL ...

Crash after generating HLODs for merged meshes that have all triangles culled

UE - World Creation - Worldbuilding Tools - HLOD - Jul 25, 2024