[samiam1000]

I think I did a mistake then..
My snappyHexMeshDict file is no bigger than 20 lines..

geometry
  {
      nasal_cavity.stl // STL filename
      {
          type triSurfaceMesh;
      }
  
      box  // User defined region name
      {
          type   searchableBox;       // region defined by bounding box
          min    (-0.0422 -0.0880 -0.576);
          max    (-0.0338 0.00583 -0.479);
      }
  
  };

Where's the problem in my file?