Now in code:
  if (this->Points)
    {
    double x[3];
    this->Points->GetPoint(lv);
    this->Points->SetPoint(v, x);
    this->Points->SetNumberOfPoints(lv);
    }
Should change to:
  if (this->Points)
    {
    double x[3];
    this->Points->GetPoint(lv,x);
    this->Points->SetPoint(v, x);
    this->Points->SetNumberOfPoints(lv);
    }
Best regards,
Naszta