Unroller AccessViolationException in Rhino.Compute

Rhino Developer compute.rhino3d
,
1

Hey everyone.

I’m currently running in a problem with rhino.compute and the unroller. In my rhino.compute config i set CreateHeadlessDoc = false.

The code is basically that…

  var unroller = new Unroller(brep)
      {
          ExplodeOutput = false,
          AbsoluteTolerance = 0.1
      };

  var res = unroller.PerformUnroll(out var c, out var up,  out var ud);

What I’m getting when running it in rhino.compute is:

Fatal error. System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
Repeat 2 times:

at UnsafeNativeMethods.CRhinoUnroll_CreateFlatBreps(IntPtr, Double, Int32 ByRef, Int32 ByRef, Int32 ByRef, Int32 ByRef)

I’m not using the doc tolerances to not access the not available doc.

When I use CreateHeadlessDoc = true it works without a problem.

My question would be:

  1. Is that a bug, or is the unroller not compatible with a headless env?
  2. What are the implications when I activate CreateHeadlessDoc = true in rhino.compute / are there any downsides?

If I remember correctly, it worked previous v8.20 I’m now on version Rhino 8 SR25 2025-11-24 (Rhino 8, 8.25.25328.11001)

Best and thank you already in advance