title: pyinstaller .exe file does not work after import another module
body: <p>I created an exe file with pyinstaller from a python file, which is shown bellow and the file worked correctly. but when i import a module like vtk or something else the generated exe file does not worked. How can i fix this issue?</p>
  <pre><code>import sys
  from PyQt5 import QtCore, QtWidgets
  from PyQt5.QtWidgets import QMainWindow
  from simulation import SimulationWindow
  
  class mainwindow(QMainWindow, SimulationWindow):
      def __init__(self, parent=None):
          super(mainwindow, self).__init__(parent)
          self.setupUi(self)
          self.show()
         
  if __name__ == &quot;__main__&quot;:
      app = QtWidgets.QApplication(sys.argv)
      demowindow = mainwindow()   
      demowindow.show()
      sys.exit(app.exec_())
  </code></pre>