Python Multi Thread

Hi, i am trying to create a simple project in which the position of a certain object is updated in a specific thread while in the others data are received from an UDP client . By now, for simplicity , i am testing only the thread related to the visual update of the object position. The problem here, is that every time i run the code it gives me a segmentation fault error . The code is here reported

def robot_handler(self):

   with ThreadLoop.event() as event:     
          while not event.is_set():                   
               for i in range(ROBOT_NUMBER):                    
                 self.robotic_line[i].target.matrix_world.translation[0] += 5 
                                        
              time.sleep(1/REFRESH_RATE)