Script Editor won't open and Python3 not working in Grasshopper

Timo_Harboe_Nielsen · February 3, 2026, 3:57pm

We have the following issue.
We have Rhino 8 and Rhino WIP (9.0.26027.12305) installed.
When placing a python component on an empty canvas in Grasshopper we get this error:

“An exception was thrown during a solution”
When clicking ok the component looks like this

Note that this works perfectly in Rhino 8.

We tried opening the script editor and got this message in the command line:

_-ScriptEditor
Select Option ( Edit  Run  Open  Test ): _Edit
Error opening script editor form | System.Text.Json.JsonReaderException: The input does not contain any JSON tokens. Expected the input to start with a valid JSON token, when isFinalBlock is true. LineNumber: 0 | BytePositionInLine: 0.
   at System.Text.Json.ThrowHelper.ThrowJsonReaderException(Utf8JsonReader& json, ExceptionResource resource, Byte nextByte, ReadOnlySpan`1 bytes)
   at System.Text.Json.Utf8JsonReader.Read()
   at System.Text.Json.JsonDocument.Parse(ReadOnlySpan`1 utf8JsonSpan, JsonReaderOptions readerOptions, MetadataDb& database, StackRowStack& stack)
   at System.Text.Json.JsonDocument.Parse(ReadOnlyMemory`1 utf8Json, JsonReaderOptions readerOptions, Byte[] extraRentedArrayPoolBytes, PooledByteBufferWriter extraPooledByteBufferWriter)
   at System.Text.Json.JsonDocument.Parse(ReadOnlyMemory`1 json, JsonDocumentOptions options)
   at System.Text.Json.JsonDocument.Parse(String json, JsonDocumentOptions options)
   at Rhino.Runtime.Code.Serialization.Json.JsonStreamReader.ReadJson(String json)
   at Rhino.Runtime.Code.Serialization.Json.JsonStreamReader..ctor(String json, JsonSerializerOptions options)
   at Rhino.Runtime.Code.Serialization.Json.JsonStream.GetReader(String json, JsonSerializerOptions options)
   at RhinoCodeEditor.Aspects.MainEditorState`1.TryFindLegacy(JsonStreamReader& reader, PersistentConfigsSchema& schema)
   at RhinoCodeEditor.Aspects.MainEditorState`1.TryLoadAsync(TEditor editor)
   at RhinoCodePlugin.Commands.ScriptEditorCommand.TryOpenEditorFormAsync(Form owner)

Note that if we use the EditPythonScript command we get to the python script editor just fine, and python works there as expected.

What we tried:
Uninstall Rhino WIP and reinstall. Issue persists.
Restart computer. Issue persists
Remove Grassshopper components both via the compnents folder and via the packagemanager. Issue persists.

This is only on a single computer.
Here is the SystemInfo from a computer where it works.

Rhino 9 SR0 2026-1-27 (Rhino WIP, 9.0.26027.12305, Git hash:master @ 5f15e63747872f59c771ecf3d824aa18e045777a)
License type: Commercial, build 2026-01-27
License details: Cloud Zoo
Expires on: 2026-03-13

Windows 11 (10.0.26200 SR0.0) or greater (Physical RAM: 32GB)
.NET 9.0.3

Computer platform: LAPTOP  - Plugged in [99% battery remaining]

Hybrid graphics configuration using DirectX
  Primary display: NVIDIA RTX 2000 Ada Generation Laptop GPU (NVidia) Memory: 8GB, Driver date: 10-12-2025 (M-D-Y).
    > Integrated accelerated graphics device with 4 adapter port(s)
        - Laptop's primary display device

Secondary graphics devices.
  Intel(R) UHD Graphics (Intel) Memory: 2GB, Driver date: 9-12-2025 (M-D-Y).
    > Integrated graphics device with 4 adapter port(s)
        - Windows Main Display is laptop's integrated screen or built-in port

DirectX Settings
  Safe mode: Off

OpenBLAS: OpenBLAS 0.3.30 DYNAMIC_ARCH NO_AFFINITY Haswell 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"	9.0.26027.12305
  C:\Program Files\Rhino 9 WIP\Plug-ins\rdk.rhp	"Renderer Development Kit"	
  C:\Program Files\Rhino 9 WIP\Plug-ins\UpdatesAndStatistics\UpdatesAndStatistics.rhp	"UpdatesAndStatistics"	9.0.26027.12305
  C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoRenderCycles.rhp	"Rhino Render"	9.0.26027.12305
  C:\Program Files\Rhino 9 WIP\Plug-ins\rdk_etoui.rhp	"RDK_EtoUI"	9.0.26027.12305
  C:\Program Files\Rhino 9 WIP\Plug-ins\NamedSnapshots.rhp	"Snapshots"	
  C:\Program Files\Rhino 9 WIP\Plug-ins\MeshCommands.rhp	"MeshCommands"	9.0.26027.12305
  C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoCycles.rhp	"RhinoCycles"	9.0.26027.12305
  C:\Program Files\Rhino 9 WIP\Plug-ins\3dxrhino.rhp	"3Dconnexion 3D Mouse"	
  C:\Program Files\Rhino 9 WIP\Plug-ins\Displacement.rhp	"Displacement"	
  C:\Program Files\Rhino 9 WIP\Plug-ins\SectionTools.rhp	"SectionTools"

And here is the system info for the computer where it DOESN’T work

Rhino 9 SR0 2026-1-27 (Rhino WIP, 9.0.26027.12305, Git hash:master @ 5f15e63747872f59c771ecf3d824aa18e045777a)
License type: Commercial, build 2026-01-27
License details: Cloud Zoo
Expires on: 2026-03-13

Windows 11 (10.0.26200 SR0.0) or greater (Physical RAM: 64GB)
.NET 9.0.1

Computer platform: LAPTOP  - Plugged in [100% battery remaining]

Hybrid graphics configuration using DirectX
  Primary display: NVIDIA RTX 2000 Ada Generation Laptop GPU (NVidia) Memory: 8GB, Driver date: 10-12-2025 (M-D-Y).
    > Integrated accelerated graphics device (shares primary device ports)
        - Laptop's primary display device

Secondary graphics devices.
  Intel(R) Arc(TM) Pro Graphics (Intel) Memory: 2GB, Driver date: 2-26-2025 (M-D-Y).
    > Integrated accelerated graphics device with 4 adapter port(s)
        - Windows Main Display is laptop's integrated screen or built-in port
        - Secondary monitor attached to adapter port #1

DirectX Settings
  Safe mode: Off

OpenBLAS: OpenBLAS 0.3.30 DYNAMIC_ARCH NO_AFFINITY Haswell 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"	9.0.26027.12305
  C:\Program Files\Rhino 9 WIP\Plug-ins\rdk.rhp	"Renderer Development Kit"	
  C:\Program Files\Rhino 9 WIP\Plug-ins\UpdatesAndStatistics\UpdatesAndStatistics.rhp	"UpdatesAndStatistics"	9.0.26027.12305
  C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoRenderCycles.rhp	"Rhino Render"	9.0.26027.12305
  C:\Program Files\Rhino 9 WIP\Plug-ins\rdk_etoui.rhp	"RDK_EtoUI"	9.0.26027.12305
  C:\Program Files\Rhino 9 WIP\Plug-ins\NamedSnapshots.rhp	"Snapshots"	
  C:\Program Files\Rhino 9 WIP\Plug-ins\MeshCommands.rhp	"MeshCommands"	9.0.26027.12305
  C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoCycles.rhp	"RhinoCycles"	9.0.26027.12305
  C:\Program Files\Rhino 9 WIP\Plug-ins\3dxrhino.rhp	"3Dconnexion 3D Mouse"	
  C:\Program Files\Rhino 9 WIP\Plug-ins\Displacement.rhp	"Displacement"	
  C:\Program Files\Rhino 9 WIP\Plug-ins\SectionTools.rhp	"SectionTools"

The system info was pulled before deleting grasshopper plugins

Japhy · February 3, 2026, 4:25pm

Hi Timo,

Lets completely reset the python environment by closing Rhino and deleting %HOMEPATH%\.rhinocode and restart Rhino

Run ScriptEditor command and let it initialize languages
Run RhinoCodeLogs, save the logs into a text file

keen · March 27, 2026, 1:40pm

Hi, I tried these steps a couple of times but haven’t been able to open the ScriptEditor window. I’m using Rhino 8 but also have the 9 WIP installed.

Rhino 8 SR30 2026-3-23 (Rhino 8, 8.30.26082.23001, Git hash:master @ abea9e77e9bb144e00d8281bfa44e613abd9d918)
License type: Commercial, build 2026-03-23
License details: Cloud Zoo

Windows 11 (10.0.22621 SR0.0) or greater (Physical RAM: 24GB)
.NET 8.0.19

Computer platform: DESKTOP

Standard graphics configuration.
Primary display and OpenGL: NVIDIA Quadro P620 (NVidia) Memory: 2GB, Driver date: 8-7-2025 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 580.97

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.
Intel(R) UHD Graphics 630 (Intel) Memory: 1GB, Driver date: 11-16-2022 (M-D-Y).

Integrated graphics device with 3 adapter port(s)

There are no monitors attached to this device!

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: 8-7-2025
Driver Version: 32.0.15.8097
Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24 bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 2 GB

Rhino plugins that do not ship with Rhino

Rhino plugins that ship with Rhino
C:\Program Files\Rhino 8\Plug-ins\Commands.rhp “Commands” 8.30.26082.23001
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\RhinoBonusTools.rhp “Rhino Bonus Tools”
C:\Program Files\Rhino 8\Plug-ins\IdleProcessor.rhp “IdleProcessor”
C:\Program Files\Rhino 8\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 8.30.26082.23001
C:\Program Files\Rhino 8\Plug-ins\RhinoRender.rhp “Legacy Rhino Render”
C:\Program Files\Rhino 8\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 8.30.26082.23001
C:\Program Files\Rhino 8\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 8\Plug-ins\MeshCommands.rhp “MeshCommands” 8.30.26082.23001
C:\Program Files\Rhino 8\Plug-ins\IronPython\RhinoDLR_Python.rhp “IronPython” 8.30.26082.23001
C:\Program Files\Rhino 8\Plug-ins\RhinoCycles.rhp “RhinoCycles” 8.30.26082.23001
C:\Program Files\Rhino 8\Plug-ins\Grasshopper\GrasshopperPlugin.rhp “Grasshopper” 8.30.26082.23001
C:\Program Files\Rhino 8\Plug-ins\RhinoCode\RhinoCodePlugin.rhp “RhinoCodePlugin” 8.30.26082.23001
C:\Program Files\Rhino 8\System\netcore\export_PDF.rhp “PDF Export” 8.30.26082.23001
C:\Program Files\Rhino 8\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 8.30.26082.23001
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”

ScriptEditor.log (30.4 KB)

Japhy · March 27, 2026, 2:36pm

Hi Keen,

This looks to be an eto version mismatch causing the issue.

Lets go to Add or Remove programs and repair Rhino. (Right click, modify, repair)

keen · March 27, 2026, 3:35pm

yes, that solved it. Thank you.

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Script Editor won't open and Python3 not working in Grasshopper

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