Unreal Engine Issues
Unreal Engine Issues
Mutable compile hangs indefinitely when using Customizable Object Extension Data Constants
UE - Anim - Mutable - Oct 25, 2025I am getting a CO compile to hang indefinitely while compiling. It seems to be caused by the optimization in LocalLogicOptimiserAST that tries to convert 3+ conditionals into a switch statement. It ...
bStaticWhenNotMoveable in Lighting category instead of Physics
UE - Simulation - Gameplay - Oct 24, 2025"UPrimitiveComponent::bStaticWhenNotMoveable"'s category is set to Lighting, not Physics. This causes it to be hidden when lighting-related properties are hidden, even though it controls physics sta ...
Variant Manager: LevelVariantSets asset corruption after rename or duplicate
UE - Editor - Content Pipeline - Oct 24, 2025When renaming or duplicating a LevelVariantSets asset that contains a Director Blueprint, the internal DirectorClass reference becomes mismatched. Although the DirectorBlueprint pointer updates corr ...
Missing materials on the rear lights and windows of library vehicles
TM - Content - Oct 24, 2025Reported in SF [Link Removed] The rear light material and window materials on Twinmotion library vehicles are not present on many vehicles in TM 2025.2. Confirmed affected vehicles are in the foll ...
Snap to nearest spline point no longer working in 5.6. Right clicking on a spline point and using the option “Snap to nearest spline point" will no longer snap that point to any nearby spline and will sometimes cause the spline to snap to itself.
UE - Gameplay - Oct 22, 2025Context: When editing SplineComponents in the level viewport, right clicking a spline point has a context menu action "Snap to nearest spline point". Problem: The problem is, Snap to nearest spline ...
World Position Offset invalidates Point Lights Entire Virtual Shadow Map Cache when light frustrum is only overlapping a small portion of the mesh
UE - Graphics Features - Oct 22, 2025When adding a spotlight to the scene it does not correctly use cached virtual shadow map pages when the spotlight overlaps a mesh using WPO. This can be most easily observed by entering 'Cached Pag ...
Child actor components fail to attach in cooked builds when mobility is set to movable and end up at the origin
UE - Gameplay - Oct 21, 2025Context: A Child Actor Component allows an actor in Unreal Engine to contain another actor as its child (component). Problem: The problem is inconsistent handling of child actor component mobility ...
Mover character no longer calls ProduceInput on server when the only client unpossesses it and disconnects
UE - Gameplay - Player Movement - Mover - Oct 21, 2025When a client disconnects/unpossesses a mover character, the character's Network Prediction Component will re-configure itself now that it does not have a net connection. However, this handling will ...
Body Setup of a Static Mesh with Simple Collision will pass validation, but removing it and using only a Complex collision and setting Collision Complexity "Use Complex as Simple" will fail validation: "Bone None requires at least one collision shape".
UE - Simulation - Gameplay - Oct 20, 2025Context: By default, Unreal Engine creates both simple and complex shapes, then, based on what the user wants (complex query versus simple query), the physics solver will use the corresponding shape ...
Children of editor-only actors do not maintain correct transforms when placed inside level instances for PIE and cooked builds
UE - World Creation - Worldbuilding Tools - Level Instances - Oct 20, 2025We have found an issue where children of editor-only actors get wrong transforms in PIE and cooked builds when placed inside level instances. This affects both engine version 5.5 and 5.6. The issue ...