diff --git a/CurveComposite.cpp b/CurveComposite.cpp
index 228752d..76edd77 100644
--- a/CurveComposite.cpp
+++ b/CurveComposite.cpp
@@ -1498,6 +1498,9 @@ CurveComposite::CopyParamRange( double dUStart, double dUEnd) const
    if ( dUStart < - EPS_PARAM  ||  dUStart > dMaxU + EPS_PARAM  ||
         dUEnd < - EPS_PARAM  ||  dUEnd > dMaxU + EPS_PARAM)
       return nullptr ;
+  // se i parametri coincidono, non resta alcunchè
+   if ( abs( dUEnd - dUStart) < EPS_PARAM)
+      return nullptr ;
   // se il parametro start supera quello di end
    if ( dUStart > dUEnd - EPS_PARAM) {
      // se curva aperta, il trim la cancella completamente quindi non resta alcunchè
diff --git a/EgtGeomKernel.rc b/EgtGeomKernel.rc
index f4d2aa3..a0bf9fe 100644
Binary files a/EgtGeomKernel.rc and b/EgtGeomKernel.rc differ