Bug: Materials black again

(9.0.26167.11545, 2026-06-16)

The material “Edelstein” was made in V9 WIP, “Seiden…” was imported from the material library.

This is the Rendered display mode:

It renders fine in Raytraced.

We had this before; it was fixed, but the error is a revenant.

“Please copy paste system info.”
OK:

Rhino 9 SR0 2026-6-16 (Rhino WIP, 9.0.26167.11545, Git hash:master @ 57b70c19c1a95d556312e40efd60cd1c4e9f7aaf)
License type: Commercial, Build 2026-06-16
License details: Cloud Zoo
Expires on: 2026-07-31

Windows 11 (10.0.26200 SR0.0) or greater (Physical RAM: 32GB)
.NET 10.0.9

Computer platform: DESKTOP

Standard graphics configuration using DirectX
Primary display: NVIDIA GeForce RTX 2070 (NVidia) Memory: 8GB, Driver date: 1-20-2026 (M-D-Y). DirectX(11)
> Accelerated graphics device with 4 adapter port(s)
- Windows Main Display attached to adapter port 0
- Secondary monitor attached to adapter port 1

Secondary graphics devices.
None found.

DirectX Settings
Safe mode: Off

OpenBLAS: OpenBLAS 0.3.30 DYNAMIC_ARCH NO_AFFINITY Zen MAX_THREADS=64.

Rhino plugins that do not ship with Rhino

Rhino plugins that ship with Rhino
C:\Program Files\Rhino 9 WIP\Plug-ins\Commands.rhp “Commands” 9.0.26167.11545
C:\Program Files\Rhino 9 WIP\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoBonusTools.rhp “Rhino Bonus-Werkzeuge”
C:\Program Files\Rhino 9 WIP\Plug-ins\UpdatesAndStatistics\UpdatesAndStatistics.rhp “UpdatesAndStatistics” 9.0.26167.11545
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 9.0.26167.11545
C:\Program Files\Rhino 9 WIP\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 9.0.26167.11545
C:\Program Files\Rhino 9 WIP\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 9 WIP\Plug-ins\MeshCommands.rhp “MeshCommands” 9.0.26167.11545
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoCycles.rhp “RhinoCycles” 9.0.26167.11545
C:\Program Files\Rhino 9 WIP\Plug-ins\Displacement.rhp “Displacement”
C:\Program Files\Rhino 9 WIP\Plug-ins\SectionTools.rhp “SectionTools”

Just in case anyone’s interested:
Still in (9.0.26174.12303, 2026-06-23).

In the Thumbnail Properties, the default lighting is skylight.
When I change it to Simple, the preview comes to life.
But only for the single thumbnail.

In any case, this is a bug.

Hmm, it fixed automagically in (9.0.26181.12303, 2026-06-30).
May I know what caused the black previews?

I do not see a bug report for this, so it may have been a temporary issue that has been fixed.

if it returns please give a shout.