diff --git a/EgtExch3dm.rc b/EgtExch3dm.rc
index 710a43a..dc65dd6 100644
Binary files a/EgtExch3dm.rc and b/EgtExch3dm.rc differ
diff --git a/Export3dm.cpp b/Export3dm.cpp
index 9f8a7a4..ee1bbdc 100644
--- a/Export3dm.cpp
+++ b/Export3dm.cpp
@@ -507,16 +507,29 @@ Export3dm::ExportSTM( const string& sName, const IGdbIterator& iIter, const Fram
   // lo porto nel frame globale
    pSrfTm->ToGlob( frFrame) ;
 
-   int nVertices = pSrfTm->GetVertexCount() ;
-   int nTriangles = pSrfTm->GetTriangleCount() ;
+   int nVertices = pSrfTm->GetVertexSize() ;
+   int nTriangles = pSrfTm->GetTriangleSize() ;
    ON_Mesh* onMesh = new ON_Mesh ;
+
+   bool bOk = true ;
    for ( int v = 0 ; v < nVertices ; ++v) {
       Point3d pt ; pSrfTm->GetVertex( v, pt) ;
-      onMesh->SetVertex( v, ConvertPoint( pt)) ;
+      bOk = onMesh->SetVertex( v, ConvertPoint( pt)) ;
+      if ( ! bOk) {
+         LOG_ERROR( GetEE3Logger(), "Export3dm SurfTm: Error adding vertex")
+         bOk = true ;
+      }
    }
+   bOk = true ;
    for ( int t = 0 ; t < nTriangles ; ++t) {
-      int nIdVert[3] ; pSrfTm->GetTriangle( t, nIdVert) ;
-      onMesh->SetTriangle( t, nIdVert[0], nIdVert[1], nIdVert[2]) ;
+      int nIdVert[3] ;
+      if ( ! pSrfTm->GetTriangle( t, nIdVert))
+         continue ;
+      bOk = onMesh->SetTriangle( t, nIdVert[0], nIdVert[1], nIdVert[2]) ;
+      if ( ! bOk) {
+         LOG_ERROR( GetEE3Logger(), "Export3dm SurfTm: Error adding triangle")
+         bOk = true ;
+      }
    }
    ON_MeshVertexFaceMap onMeshVertMap ;
    onMeshVertMap.SetFromMesh( onMesh, false) ;