Unreal Engine Issues
Unreal Engine Issues
Cook Non-Determinism in USplineComponent
UE - Editor - 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 ...
Editor crash while saving asset during cook operation
UE - Core - Data Pipeline - Cooker - Apr 2, 2025It is possible to experience an editor crash in 5.5.4 when the cook process generates a warning that references an asset while the editor is saving. It seems that during a save operation, the code t ...
Inaccurate Panning on Tap Delay Submix
UE - Audio - Oct 5, 2021The panning in the Tap Delay Submix Effect does not always match its assigned Pan in Degrees value. Specifically, the left and right side appear to be reversed on Stereo setups. In addition, in 5.1 ...
NPC - Instances does not get updates from changes to the parent Niagara Parameter Collection in the editor
UE - Rendering - Architecture - Niagara - Oct 4, 2024When an Niagara Parameter Collection (NPC) is selected as the parent Collection for an NPC Instance (NPCI), all of its current parameters are carried over to the NPCI with their current values as th ...
[CrashReport] UE4Editor_Engine!operator new<FBatchedLine,FDefaultAllocator>() [array.h:2812]
OLD - Anim - Jun 2, 2016Error message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 804] Array index out of bounds: 175 from an array of size 171 Source Context: 2797 2798 temp ...
Destructibles using Form Extended structures with rigid body collision gives wrong hit result
UE - Simulation - Physics - Destruction - Jan 7, 2015DESCRIPTION: When using form extended structure with DMs that are hit by a rigid body the resulting hit does not reflect the correct actor if they are both using form extended. If a DM without form ...
A LevelSequence will lose the binding to objects contained in a level instanced inside another level
UE - Engine Scaling - Streaming - Level Instances - Sep 15, 2025A LevelSequence will lose the binding to objects contained in a level instanced inside another level on 5.6 and up. Refer to the reproduction steps or the shared repro project provided by the licens ...
DynamicEntryBox with EntryBoxType Radial is stacking Entries if SectorCentralAngle is multiple of 360.0f and DistributeItemsEvenly is enabled
UE - AI Workflows - UI Systems - May 27, 2025DynamicEntryBox with EntryBoxType Radial is stacking Entries if SectorCentralAngle is multiple of 360.0f and DistributeItemsEvenly is enabled. The licensee has provided an analysis: On void SRadia ...
Build failure after nativizing any child Blueprint class with function override (regression).
UE - Gameplay - Blueprint - Jun 7, 2018Nativization regression in 4.20 preview 1. Cannot nativize overridden functions. Log Output:UATHelper: Packaging (Windows (64-bit)): D:/Projects/Unreal/NativizeMethod/Intermediate/Plugins/Nativized ...
Capsule component Shape values can be glitched inside of Actor class bp
UE - Gameplay - Components - Oct 29, 2015Capsule component Shape values can be glitched inside of Actor class bp This effects 4.9.2 and 4.10 Preview 3, however it is working properly in 4.11-2736016 User Description: Alright, so the Cap ...