Unreal Engine Issues
Unreal Engine Issues
Crash when using StaticDuplicateObject with mismathced Source and Destination class types
UE - Core - Systems - Jun 19, 2025Starting in Unreal Engine 5.4, StaticDuplicateObject internally switched to using Unversioned Property Serialization (UPS) for performance reasons. However, UPS assumes the source and destination ob ...
Physics constraint component doesn't work when placed inside a child actor, while using world partition and streaming is enabled
UE - Runtime - Simulation - Mar 21, 2025Context: In a World partition level, to reduce complexity and provide a scalable solution when creating new projects, grid cell streaming can be enabled. Problem: The problem is that physics constr ...
Open a level that contains instanced meshes (with built lighting) will crash the editor
UE - Graphics Features - Mar 14, 2015Open a level that contains instanced meshes will crash the editor. Per the users description, the level must have had lighting built and then another level loaded or the editor restarted. Once the ...
Open a level that contains instanced meshes (with built lighting) will crash the editor
UE - Graphics Features - Mar 19, 2015Open a level that contains instanced meshes will crash the editor. Per the users description, the level must have had lighting built and then another level loaded or the editor restarted. Once the ...
Duplicate slots being created in Anim Slot Manager
OLD - Anim - Dec 11, 2015Duplicate slots are being created automatically under the Default Group in the AnimSlotManager. This is causing some problems because it replaces the originally created slot with the duplicate in t ...
Linux editor can fail on start due to a stale TPS library in Engine/Binaries/Linux
UE - Platform - Linux - May 21, 2015For 4.8, we moved LinuxNativeDialogs, a third-party library, to a different location (and also changed its API somewhat, so the old library is binary incompatible). However, some users apparently a ...
FNiagaraScalabilityManager incorrectly reactivates a NiagaraComponent that was deactivated by runtime user code
UE - Niagara - Oct 1, 2025Context: The Niagara System is the primary tool to do visual effects inside Unreal. Niagara systems can be culled due to distance. Problem: Once a deactivated Niagara System is culled due to distan ...
Using PC_Enum instead of PC_Byte with CreatePin results in incorrect pin
UE - Gameplay - Blueprint Editor - Jul 23, 2021This is a bug that can make it confusing for users (and internal devs) to make custom nodes related to enums. This is occuring because the PC_Enum type was added after the original PC_Byte but ...
Virtual Shadow Maps on Spot Lights cause a blocky presentation similar to an incorrect mip level
UE - Graphics Features - Shadows - May 26, 2025Spot Lights may present with very blocky shadow artefacts when a long attentuation radius is provided with a small cone angle. In extreme cases, this causes the VSMs to invalidate every frame. Notab ...
Material base color is lighter on Nanite meshes when using 16-bit GBuffer
UE - Graphics Features - Nanite - Aug 6, 2024The base color is brighter on Nanite meshes than non-Nanite meshes when GBuffer Format is set to "Force 16-bits per channel" (r.GBufferFormat 5) even though the meshes are using the same material. ...