Last 8 SR broken rhinocommon stl export

Rhino Developer
1

Hi all.
Latest Rhino 8 Service Release (8.24.25281.15001, 2025-10-08) broken stl export through Rhinocommon.

RhinoDoc export = RhinoDoc.CreateHeadless(null);
export.Objects.Add(mymesh);
export.Export(Path.Combine(stlpath));
export.Dispose();

Rhino 8 fully crash and close without any warning at all!

This just broke my whole workflow! I’ll probably avoid updating for months now. :frowning:
I need to revert to previous version ASAP!
Please how do I do so?

My last properly exported .stl this way have this header:
“Rhinoceros Binary STL ( Sep 8 2025 )”

Reverted to 8.23.25251.13001, 2025-09-08 same .gh script is working fine.

My c# is from Rhino 7, but even creating a simple c# with the code above with the new editor in 8 give the same problem:

  • 8.24.25281.15001, 2025-10-08 crash without warning or log
  • 8.23.25251.13001, 2025-09-08 everything fine
2

@tim - can you look into this?

3

Hi Riccardo,

I can’t repeat this testing here in the debugger. This is the code I’m using based off of yours.

 [CommandStyle(Rhino.Commands.Style.Hidden)]
 public class TestHeadlessFileExport : Rhino.Commands.Command
 {
   public TestHeadlessFileExport()
   {
     TheCommand = this;
   }

   /// <summary>The one and only TestHeadlessFileExport object instance</summary>
   public static TestHeadlessFileExport TheCommand { get; private set; }

   ///<returns>The command name as it appears on the Rhino command line.</returns>
   public override string EnglishName
   {
     get { return "TestHeadlessFileExport"; }
   }

   protected override Result RunCommand(RhinoDoc doc, RunMode mode)
   {
     GetObject go = new GetObject();
     go.GeometryFilter = ObjectType.Mesh;
     if (GetResult.Object != go.Get())
       return Result.Cancel;

     Mesh mesh = go.Object(0).Mesh();
     if (null == mesh)
       return Result.Failure;

     RhinoDoc export = RhinoDoc.CreateHeadless(null);
     export.Objects.Add(mesh);
     export.Export(Path.Combine("C:\\Users\\tim\\Desktop\\junk.raw"));
     export.Dispose();
     return Result.Success;
   }
 }

This iteration I tried exporting to raw but stl worked fine too, just changing the extension. Is it limited to a specific model? If yes, can you share that? You can upload it here if it’s not for public consumption.

Tim

4

I tried on another machine:
It was on 8.18.25100.11001, 2025-04-10 , it works!

After update to 8.24.25281.15001, 2025-10-08 trying to run the same .gh result in a silent CTD without error log or backup…

rhinocommon stl export.gh (7.2 KB)

Now that you made me update another, totally different machine I have less doubts than before that this is indeed a new bug of this specific SR.

Tell me if you need me providing more “proof” of the problem… I’ll install 8 on my cheap laptop if needed.