diff --git a/API_MachMgr.cpp b/API_MachMgr.cpp
index 4217fd8..f4cb02e 100644
--- a/API_MachMgr.cpp
+++ b/API_MachMgr.cpp
@@ -1446,11 +1446,15 @@ __stdcall EgtGetMachiningGeometry( int nInd, int* pnId, int* pnSub)
       return FALSE ;
   // recupero elenco identificativi
    SELVECTOR vIds ;
-   if ( ! ExeGetMachiningGeometry( vIds))
+   if ( ! ExeGetMachiningGeometry( vIds)) {
+      *pnId = GDB_ID_NULL ;
       return FALSE ;
+   }
   // verifico indice
-   if ( nInd < 0  ||  nInd >= int( vIds.size()))
+   if ( nInd < 0  ||  nInd >= int( vIds.size())) {
+      *pnId = GDB_ID_NULL ;
       return FALSE ;
+   }
   // assegno il risultato
    *pnId = vIds[nInd].nId ;
    *pnSub = vIds[nInd].nSub ;
diff --git a/EgtInterface.rc b/EgtInterface.rc
index b706036..4dd8939 100644
Binary files a/EgtInterface.rc and b/EgtInterface.rc differ