Rhinocompute plugin – SettingsDirectoryHelper crashes when loading

Rhino Developer compute.rhino3d
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Environment

  • Rhino 7 (compute host on Windows Server via IIS; app pool runs rhino.compute.exe)
  • App pool: COMPUTE_PLUGINS=CalEnv.Compute.rhp;SciEnv.Compute.rhp;SciEnv.Apertures.Compute.rhp;SciEnv.Build.rhp
  • LoadUserProfile=True (verified)
  • APPDATA/LOCALAPPDATA explicitly set to writable paths: C:\inetpub\wwwroot\rhino.compute\appdata\Roaming and …
    \Local
  • Plug-in: SciEnv.Build (GUID currently F4B0C3A2-52A8-4B9F-A39F-5E6F4E4C4D91)
  • Tried: new GUID, new user profile, Safe Mode, blocking all other plug-ins, minimal plug-in (no settings code),
    pre-creating plug-in settings folders.

Symptom

  • OnLoad shows a Rhino “object reference” dialog, and the plug-in never appears in /plugins/rhino/installed; HTTP
    endpoints return 404.
  • Our OnLoad completes and registers endpoints (log shows “Registered endpoint …” and “OnLoad success”).
  • Immediately after, Rhino throws in its own settings resolver.

Log (from scienv-build.log)

[FirstChance] System.IndexOutOfRangeException: Index was outside the bounds of the array.
at Rhino.PlugIns.PlugIn.SettingsDirectoryHelper(Boolean bLocalUser, Assembly assembly, Guid pluginId)
[FirstChance] System.NullReferenceException: Object reference not set to an instance of an object.
at Rhino.PlugIns.PlugIn.InternalOnLoad(Int32 pluginSerialNumber)

(Repeated every load attempt; same on fresh user profile and in Safe Mode.)

What we tried

  • Rotated plug-in GUID; reinstalled.
  • Cleared/created settings dirs under AppData (Roaming/Local) for the plug-in GUID.
  • Set APPDATA/LOCALAPPDATA to known writable paths; restarted app pool.
  • New Windows user, Safe Mode, blocking other plug-ins.
  • Minimal plug-in (no settings code, no extra handlers).

Other plug-ins

  • CalEnv.Compute, SciEnv.Compute, and SciEnv.Apertures.Compute load fine on the same host.

Request

  • Is there a Rhino 7 SR/hotfix for SettingsDirectoryHelper throwing IndexOutOfRange/NullReference in headless/
    compute contexts?
  • Any supported way to bypass settings resolution for a compute plug-in in Rhino 7?
  • Guidance on additional diagnostics to capture the path Rhino is constructing in SettingsDirectoryHelper.

Thanks for any pointers or patches—this is blocking plug-in load in compute (endpoints 404).