No valid file to be loaded /root/.ros"

[Lejou]

I have a problem. When the button 4)estimate_model pressed, the terminal shows "No valid file to be loaded /root/.ros"(seen on the left of the following picture). What kind of the file should be loaded here? I checked the source, there were two "error info"(seen on the right of the following picture). I doubt that is there something I set incorrectly? How can I define the address where I can save the estimation results?

Moreover, on the right of the above picture, in the line 148 in rosdyn_par_estim_interface.cpp, there indicates that "Find all the files that need to be loaded":

  // Find all the files that need to be loaded
  std::string dir = test_path_ + "/";
  std::vector<std::string> files = std::vector<std::string>();

  if (getdir(dir, files))
  {
    ROS_ERROR("No valid file to be loaded %s\n", test_path_.c_str());
    m_result_.status = rosdyn_identification_msgs::MetoParEstimResult::GENERIC_ERROR;
    m_meto_par_estim_as->setAborted(m_result_);
    return;
  }

while the vector "files" is empty. What kinds of files are necessary here? And, if the file would be saved in the "/root/.ros", should I launch the rviz also in the root or with a super permission?