Unreal Engine Issues
Unreal Engine Issues
ULevelSequence trying to duplicate a REINST_ class when creating new custom binding in ConvertOldSpawnables()
UE - Framework - Blueprint Compiler - Jul 23, 2025The assert that we're hitting is:Cannot replace existing object of a different class. New Object: /Engine/Transient.REINST_BPC_NPC_VFX_C_230 /Game/Maps/[REDACTED]/Levels/[REDACTED]/LevelSequence/ ...
Artifacts appear on translucent particle systems during camera motion blur
UE - Rendering Architecture - Jul 23, 2025Translucent particle systems exhibit visual artifacts when the camera moves, even though motion vectors are disabled for the particle emitters. While switching the Translucency Pass to "After Motio ...
Farfield shadow in lumen scene
UE - Graphics Features - Jul 21, 2025Shadows in the Lumen Scene from Lumen's Direct Lighting do not match the world when in the Lumen Far Field. This leads to shadows where there should not be any, and missing shadows where there shou ...
Montage Editor: Mouse Wheel Cannot Scroll to the Bottom of notify section when there are many track.
UE - Anim - Runtime - Jul 21, 2025When a large number of notify tracks are added in the Montage Editor, the mouse wheel scroll does not allow the user to reach the bottom-most tracks. Only by manually dragging the scrollbar can the ...
Performance slowdown when ray tracing is disabled due to SetResidencyPriority
UE - Rendering Architecture - RHI - Jul 17, 2025When a game is compiled with ray tracing disabled (D3D12_RHI_RAYTRACING=0) and the GPU the game is running on becomes low on VRAM, frame time is negatively impacted and doesn't recover. The D3D12_RH ...
Niagara Regression - Looping particle with Spawn Burst Instantaneous on time 0.0 flickers for a frame between loops
UE - Niagara - Jul 16, 2025Note: This worked correctly up to UE 5.4, but repros from UE 5.5 up to mainline latest. If a Niagara Emitter is set up with "Spawn Burst Instantaneous" on time 0.0, and the spawned particle(s) have ...
Bake Pose is not applied correctly when using LODSettings asset
UE - Anim - Rigging - Jul 16, 2025The Bake Pose setting does not work when using a SkeletalMesh LODSettings asset. After the change in CL22878911, the BasePose in the LODSettings asset is no longer copied to the BakePose in the skel ...
When moving actors to the current level, their label is reset and displayed incorrectly on the Scene Outliner until the next time it is refreshed
UE - Editor - Workflow Systems - Jul 14, 2025This is a regression, it worked correctly up to UE 5.4, but repros on UE 5.5 and 5.6. Also, this seems related to [Link Removed], which was fixed by CL 40649716/40649749 and integrated into UE 5.6, ...
Channel Mask Parameter does not correctly pull through the Alpha channel from
UE - Rendering Architecture - Materials - Jul 8, 2025The ChannelMaskParameter node in the Material Graph works in most cases, but unusually does not work when extracting the value of the Alpha channel only for Vertex Color input data. ...
Assigning a static mesh to a Mutable Clip Mesh With Mesh Node can crash the editor
UE - Anim - Mutable - Jul 4, 2025Context: The Mutable plugin has a modifier node called Clip Mesh With Mesh that allows Static Mesh modifiers to be assigned as the clip mesh. Under certain circumstances, an assert can be triggered ...