Grasshopper stopped launching after updating to Rhino 8 SR35

Rhino Rhino for Windows
1

Hello,

Grasshopper stopped working immediately after I updated Rhino 8 to SR35.

Rhino version:
Rhino 8 SR35 — 8.35.26251.13001
Build date: 2026-09-08
Windows
Educational license — Cloud Zoo

Before updating to SR35, Grasshopper was working normally. After the update, Grasshopper no longer starts and shows the following error:

The type initializer for 'Grasshopper.GUI.Canvas.GH_Canvas' threw an exception.

I have already tried the following:

  • Removed all third-party Grasshopper plugins.
  • Reinstalled/repaired Rhino.
  • Checked the .NET environment.
  • Checked Windows Event Viewer; there is no relevant error.
  • Windows Smart App Control is disabled.
  • The problem persists with no third-party Grasshopper plugins installed.
  • GrasshopperLoadOneByOne is also unavailable because Grasshopper does not finish loading.

The problem started immediately after updating to SR35, so I suspect there may be a regression or compatibility issue introduced in this release.

Is this a known issue with SR35? Is there a recommended workaround or diagnostic procedure to identify what is preventing GH_Canvas from initializing?

Thank you.

2

none of this sounds familiar and you’ve got through they typical troubleshooting. I will send you the latest to install to see if that helps, as well as an older version. It wouldn’t hurt to try the Rhino Beta as well.

What is your full Rhino SystemInfo?