solved the problem by
"delete HKEY_CURRENT_USER\Software\McNeel\Rhinoceros from the registry and then reinstall the plugin."

it just started to fail to load the plugin today.

my Rhino Version is 7 SR11(7.11.21293.9001.2021-10-20)
my Octane standalone version 2020.2.5, and is rendering my old .ocs scene correctly.
my downloaded plugin version is OctaneRenderForRhino7_2020_2_3_125_ENTERPRISE
my graphics card is NVIDIA ...

Thank you Paul for replying!!
right, that is my work around, and it still requires me to re-assemble each ORBX into one scene...

Is there a function, when exporting Rhino scene as .ocs or .orbx, to export the mesh into separated geometry groups, instead of one big chunk of geometry??
maybe separated by Rhino layers??

i understand each Rhino blocks are kept separate from other mesh, but not all geometry in Rhino will be made ...

I just wanted to share a YouTube video i made, talking about how we can use Octane for Rhino in the process of set design, construction, and presentation for a film production.
Here i declared "Rhino with Octane is the best and only way forward."
https://youtu.be/BHecC3R-l10

In this video, i am ...

Roy,
i think Bongo is the right answer here.
Easiest workflow in my opinion is to "Export Bongo animation to ORBX", then you can render the animation with Octane Standalone.

this is my request for the future versions of the plug in.

currently it is very useful that we can assign the render target to a view.
in my personal opinion, it will be very useful if we can assign the render target to a "snapshot" instead of a view.

Snapshots have more functionalities than named ...

actually, you were right on both issue.
the minute i changed the current render to Octane, the material preview looks great, the slider works fine, and the focus and collapse status are kept, leaving no bugs at all!!
this is great!!

thank you so much Paul for sticking with us, the minority 4K ...

http://narra.jp/2018-06-0711_13_00.jpg

- the RGB node looks good
- slider shows up okay
- the material preview not working again

the palette refreshing bug is still there, thus not practical to operate with slider because every time i touch the slider, it goes back to the top.
and the collapse ...

http://narra.jp/2018-06-0623_26_24-.jpg
this ver sion 3.8.1.92 is giving me the best experience ever.
readable material/setting pallette, visible checkbox, working material preview!
i have been using Octane for Rhino from ver1, but this is the first time i'm experiencing this, which is awesome ...