Grasshopper unknown command

Grasshopper
1

Hello, I’m on Rhino 8, when I click on the grasshopper button, it’s telling me: Unknown command: _Grasshopper.

When I go to the plugins, GH is not loaded. If I’m trying to load or to install it through “GrasshopperPlugin.rhp”, I get this message:

What I tried so far:

  • Repairing the software, dind’t help
  • Unistall Rhino, reinstall it, dind’t help

I have the plugins RhinoNature and VisualArq installed, could that cause the issue?

If someone has an idea, please let me know, I don’t know what to do anymore.

2

Hi Ives -
Is the plug-in enabled in the Rhino plug-in manager?
Also, please run the Rhino SystemInfo command and copy-paste its output here.
-wim

3

Hi Wim,

no, the plugin is not loaded and can’be loaded. It’s always showing me an error message about the GH.Canvas.

Systeminfo:

Rhino 8 SR28 2026-2-10 (Rhino 8, 8.28.26041.11001, Git hash:master @ b7874a05a6982d0419fcc4f6009b510b48a09cb3)
License type: Commercial, build 2026-02-10
License details: Cloud Zoo

Windows 10 (10.0.19045 SR0.0) or greater (Physical RAM: 32GB)
.NET Framework 4.8.9310.0

Computer platform: DESKTOP

Standard graphics configuration.
Primary display and OpenGL: NVIDIA Quadro RTX 4000 (NVidia) Memory: 8GB, Driver date: 11-13-2024 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 553.35

Accelerated graphics device with 4 adapter port(s)

  • Windows Main Display attached to adapter port #0

OpenGL Settings
Safe mode: Off
Use accelerated hardware modes: On
GPU Tessellation is: On
Redraw scene when viewports are exposed: On
Graphics level being used: OpenGL 4.6 (primary GPU’s maximum)

Anti-alias mode: 4x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: High

Vendor Name: NVIDIA Corporation
Render version: 4.6
Shading Language: 4.60 NVIDIA
Driver Date: 11-13-2024
Driver Version: 31.0.15.5335
Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24 bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 8 GB

Rhino plugins that do not ship with Rhino
C:\Users\Z440\AppData\Roaming\McNeel\Rhinoceros\8.0\Plug-ins\D5Conv (e0d5e210-02f6-4ee9-a2b0-1675e225d958)\0.12.0.0028\Rhino 8\D5Conv.rhp “D5 Sync for Rhino”
C:\Program Files\SimLab\Plugins\SimLab PDF From Rhino\SimLabPDFExporter.rhp “SimLab PDF Exporter”
C:\Users\Z440\AppData\Roaming\McNeel\Rhinoceros\packages\8.0\NVIDIADenoiser\0.4.3\NVIDIADenoiser.Windows.rhp “NVIDIADenoiser.Windows” 0.4.3.0
C:\Program Files\Rhino 8\Plug-ins\Tibidabo\VisualARQ.rhp “VisualARQ”
C:\Program Files\Doliwa Workshop\Rhino Nature\Rhino Nature.rhp “Rhino Nature” 1.0.4.16355
C:\Users\Z440\AppData\Roaming\McNeel\Rhinoceros\packages\8.0\LookXRender\1.0.1\LookXRender.rhp “LookXRender” 1.0.1.0
C:\Program Files\Rhino 8\Plug-ins\Tibidabo\Tibidabo.rhp “Tibidabo”

Rhino plugins that ship with Rhino
C:\Program Files\Rhino 8\Plug-ins\Commands.rhp “Commands” 8.28.26041.11001
C:\Program Files\Rhino 8\Plug-ins\WebBrowser.rhp “WebBrowser”
C:\Program Files\Rhino 8\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 8\Plug-ins\RhinoScript.rhp “RhinoScript”
C:\Program Files\Rhino 8\Plug-ins\AnimationTools.rhp “AnimationTools”
C:\Program Files\Rhino 8\Plug-ins\IdleProcessor.rhp “IdleProcessor”
C:\Program Files\Rhino 8\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 8.28.26041.11001
C:\Program Files\Rhino 8\Plug-ins\RhinoRender.rhp “Legacy Rhino Render”
C:\Program Files\Rhino 8\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 8.28.26041.11001
C:\Program Files\Rhino 8\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 8\Plug-ins\MeshCommands.rhp “MeshCommands” 8.28.26041.11001
C:\Program Files\Rhino 8\Plug-ins\IronPython\RhinoDLR_Python.rhp “IronPython” 8.28.26041.11001
C:\Program Files\Rhino 8\Plug-ins\RhinoCycles.rhp “RhinoCycles” 8.28.26041.11001
C:\Program Files\Rhino 8\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 8.28.26041.11001
C:\Program Files\Rhino 8\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 8\Plug-ins\Displacement.rhp “Displacement”
C:\Program Files\Rhino 8\Plug-ins\SectionTools.rhp “SectionTools”

Thanks a lot

4

Hi Ives -

I’m not sure what that means.
When you are in the plug-in manager, and check the box for Grasshopper and close and reopen the Rhino Options, is the plug-in still checked? What after a restart? All this without trying to actually run Grasshopper.
-wim

5

When I’m trying to load the Grasshopper plugin (right click, then load), I get the following message:

GH Plugin
GH Plugin1409×1102 220 KB

So the plugin is never loaded. When I’m trying to install it from the Grasshoper.rhp, I get the same message.

Restart didn’t help, neither the reinstallation of Rhino 8 helped.

6

Hi Ives -

Why are you running in .NET Framework 4.8?
What happens when you switch to the default .NET Core v8?
-wim

7

Hi Wim,

Thanks a lot! I switched it to .NET Core v8 and now everything is running again!!
I think I had changed it a while back because of the RhinoNature plug‑in.
I didn’t touch that setting recently though, so it’s a bit strange that Grasshopper suddenly stopped working.

Anyway, your help is really appreciated!