Python3(c#) failing in Rhino 9 Beta (even after deleting .rhinocode)

[TAB]

Hello McNeel team,

I am experiencing an issue in Rhino 9 Beta where both the Python 3 and C# scripting components do not load properly.

In Grasshopper, the Python 3 component shows the error:
“1. Value cannot be null. (Parameter ‘source’)”

In the Script Editor, Python 3 also fails to initialize and shows:
“Error Initializing Python 3”

I also tried removing the .rhinocode folder, but the problem still persists.

Could you please advise what might be causing this issue and how I can fix it?
Thank you very much for your time and support.

@eirannejad

[Japhy]

Hi TAB,

Lets get some more info to track this down :

1. Run _RhinoCodeLogs in the rhino command line and post the log contents. If that doesn’t open, grab the latest file from %USERPROFILE%\.rhinocode\logs and post it here.
2. Run _SystemInfo in the rhino command line and post the results as well.
3. Do you have antivirus or a firewall in the mix? The python runtime gets deployed on first use and we’ve seen security software quietly block parts of it.
4. Is your Windows user folder redirected to OneDrive, or does your username have any special characters in it? Both have caused this before.

Also, when you deleted the .rhinocode folder — was Rhino fully closed at the time? If it was running, parts of it stay locked and the rebuild is incomplete. Worth closing Rhino, deleting it again, then starting fresh.

Thanks!