Unreal Engine Issues
Unreal Engine Issues
"Move Selection to Current Level" can duplicate actors when cancelling
UE - Editor - Workflow Systems - Apr 17, 2026When moving an Actor that is referenced in the source level, UEditorEngine::CopySelectedActorsToClipboard will try to select the Actor for delete which will pull the \"Delete Referenced Actor\" dial ...
UPlacementSubsystem does not respect AssetFactories priorities, which is inconsistent with UEditorEngine::ActorFactories and makes it impossible to override placed actor type when dragging asset from Content Browser to Level Editor Viewport.
UE - Editor - Workflow Systems - Mar 30, 2026Note: This issue was reproduced in UE 5.7, and it works correctly in UE 4.27. Prior to CL 24938100 (between UE 5.1 and 5.2), all existing factories were discovered and registered during engine init ...
Cook Non-Determinism in USplineComponent
UE - Editor - Workflow Systems - Feb 25, 20261. Non-Deterministic LastAuthority Serialization LastAuthority is assigned in USplineComponent::Serialize. Its value depends on the order in which the object and its archetype are serialized, leadi ...
FDetailGroup::AddGroup does not correctly apply the default expansion state for DetailGroups
UE - Editor - Workflow Systems - Feb 10, 2026There is a bug affecting DetailGroups in the engine. When adding child DetailGroups to a parent DetailGroup, the expansion state does not behave as expected and ignores the flags intended to control ...
Drag and drop does not work from a window created with PySide
UE - Editor - Workflow Systems - Feb 5, 2026The cursor position is no longer updated during drag and drop, so drag-over events cannot respond correctly. Commenting out the following code in WindowsCursor.cpp works as a workaround ( the behavi ...
In the level editor, when configuring a component that is part of an actor blueprint, adding entries to a TMap with C++ enum keys results in duplicate keys and an incorrect warning popup.
UE - Editor - Workflow Systems - Jan 22, 2026Note: This started happening in UE 5.4 and persists up to latest. It is probably related to [Link Removed] Closed ([Link Re ...
Custom thumbnails don't get updated until the asset is saved
UE - Editor - Workflow Systems - Dec 4, 2025This is a regression, here's the repro in FN/Main (48954958) : [Link Removed] And now in UE5.7 (48496583) : [Link Removed] ...
Crash when saving after resetting Instanced array element via Property Matrix on placed actors
UE - Editor - Workflow Systems - Nov 21, 2025When an Actor Component contains an Instanced UObject array marked EditDefaultsOnly, adding a new element to the Blueprint defaults correctly updates the Blueprint and its own Property Matrix. Howev ...
Unshelving a file from Unreal locks unreal. Killing process leaves the file locked and can't be checked out
UE - Editor - Workflow Systems - Nov 17, 2025Unreal currently locks any assets that are loaded. Actions such as "revert" from within the editor handle this properly by unloading the asset but unshelving from within the editor does not respect ...
Ensure triggered inside Range Struct Customization when Property Node is no longer valid (e.g. when editing FFloatRange while FRuntimeFloatCurve editor is visible) [Ref. UE-341339]
UE - Editor - Workflow Systems - Nov 12, 2025[Link Removed] Closed was fixed by CL 46990575, successfully avoiding an ensure condition inside FIntervalStructCustomization::S ...