diff --git a/libsrc/core/archive.hpp b/libsrc/core/archive.hpp
index 6db37a07..d7546060 100644
--- a/libsrc/core/archive.hpp
+++ b/libsrc/core/archive.hpp
@@ -57,6 +57,17 @@ namespace ngcore
   };
   
   
+
+  
+  template <typename T, typename = void>
+  class has_shallow_archive : public std::false_type {};
+  
+  template <typename T>
+  class has_shallow_archive<T, std::void_t<decltype(T::shallow_archive)>>
+    : public std::is_same<decltype(T::shallow_archive), std::true_type> {};
+  
+
+  
 #ifdef NETGEN_PYTHON
   pybind11::object CastAnyToPy(const std::any& a);
 #endif // NETGEN_PYTHON
@@ -501,7 +512,7 @@ namespace ngcore
     template <typename T>
     Archive& operator & (std::shared_ptr<T>& ptr)
     {
-      if constexpr(has_shared_from_this2<T>::value)
+      if constexpr(has_shallow_archive<T>::value)
         if (shallow_to_python)
           {
             Shallow (ptr);
diff --git a/libsrc/meshing/hprefinement.cpp b/libsrc/meshing/hprefinement.cpp
index bb250aee..2c59be5d 100644
--- a/libsrc/meshing/hprefinement.cpp
+++ b/libsrc/meshing/hprefinement.cpp
@@ -678,7 +678,7 @@ namespace netgen
 
     // prepare new points  
     
-    fac1 = max(0.001,min(0.33,fac1));
+    // fac1 = max(0.001,min(0.33,fac1));
     PrintMessage(3, " in HP-REFINEMENT with fac1 ", fac1); 
     *testout << " in HP-REFINEMENT with fac1 " << fac1 <<  endl; 
    
diff --git a/libsrc/occ/occ_edge.cpp b/libsrc/occ/occ_edge.cpp
index 0c907d78..4805bb17 100644
--- a/libsrc/occ/occ_edge.cpp
+++ b/libsrc/occ/occ_edge.cpp
@@ -61,7 +61,12 @@ namespace netgen
     void OCCEdge::ProjectPoint(Point<3>& p, EdgePointGeomInfo* gi) const
     {
         auto pnt = ng2occ(p);
-        GeomAPI_ProjectPointOnCurve proj(pnt, curve, s0, s1);
+        // extend the projection parameter range, else projection might fail
+        // for an endpoint
+        // see discussion here: https://forum.ngsolve.org/t/how-to-apply-occidentification-correctly/2555
+        // I do not see a better way using occ tolerances?
+        double eps = 1e-7 * (s1-s0);
+        GeomAPI_ProjectPointOnCurve proj(pnt, curve, s0-eps, s1+eps);
         pnt = proj.NearestPoint();
         if(gi)
             gi->dist = (proj.LowerDistanceParameter() - s0)/(s1-s0);