So what I would suggest is trying to eliminate potential issues one by one. It might help to zero in on the problematic mesh/material.
Start with disabling anything related to Niagara:
r.RayTracing.Geometry.NiagaraRibbons=0 r.RayTracing.Geometry.NiagaraSprites=0 r.RayTracing.Geometry.NiagaraMeshes=0Then you could also try disabling:
r.RayTracing.Geometry.SplineMeshes=0 r.RayTracing.Geometry.Text=0 r.RayTracing.Geometry.Cable=0Then anything that runs through dynamic update:
r.RayTracing.Geometry.StaticMeshes.WPO=0 r.RayTracing.Geometry.SkeletalMeshes=0If none of those work it would probably suggest that it’s a problem with one of the static meshes (and it will be more difficult to pinpoint which one). You can confirm that with r.RayTracing.Geometry.StaticMeshes and/or r.RayTracing.Geometry.NaniteProxies depending on if you use Nanite or not. Ideally set them both to 0.