[KDL] Trajectory Generator - Path_RoundedComposite

Dear All,

I am trying to create a simple component for trajectory generator purpose, using Path_RoundedComposite. I am following the example trajectory_example.cpp for that, but I keep catching the following exception:

3.562 [ ERROR ][Logger] Circle : Plane for motion is not properly defined

What is the exact meaning of this? And why is not properly defined? ( = what am I doing wrong?) (To be sure, I used the same values/viaponts used in the example, same velocity profile parameterization and so on....)

I report below part of the code interested...

     _path.reset(new KDL::Path_RoundedComposite(0.2,0.01,new KDL::RotationalInterpolation_SingleAxis()));
     _path->Add(KDL::Frame(KDL::Rotation::RPY(M_PI,0,0), KDL::Vector(-1,0,0)));
     _path->Add(KDL::Frame(KDL::Rotation::RPY(M_PI/2,0,0), KDL::Vector(-0.5,0,0)));
     _path->Add(KDL::Frame(KDL::Rotation::RPY(0,0,0), KDL::Vector(0,0,0)));
     _path->Add(KDL::Frame(KDL::Rotation::RPY(0.7,0.7,0.7), KDL::Vector(1,1,1)));
     _path->Add(KDL::Frame(KDL::Rotation::RPY(0,0.7,0), KDL::Vector(1.5,0.3,0)));
     _path->Add(KDL::Frame(KDL::Rotation::RPY(0.7,0.7,0), KDL::Vector(1,1,0)));
    _path->Finish();
    
    _vel_profile.reset(new KDL::VelocityProfile_Trap(0.5,0.1));
    _vel_profile->SetProfile(0,_path->PathLength());
    _traj.reset(new KDL::Trajectory_Segment(_path.get(),_vel_profile.get()));
    
    _max_duration = KDL::max(10, _traj->Duration());
    _time_passed = 0;
    _time_begin = os::TimeService::Instance()->getTicks();
    }
    catch(KDL::Error& e)
    {
      log(Error) << e.Description() << endlog();
      return false;
    }
Thank You in advance! - Enea Scioni