try fix

Controll.py

@@ -10,13 +10,15 @@ sess.add_all()
 controllers = {dev.serial: DeviceController(dev) for dev in sess.devices}
 serials = list(controllers.keys())
 
+startGUI()
+
 for i, serial in enumerate(serials):
     c = controllers[serial]
     c.set_mode(0, pysmu.Mode.SIMV)  # CH A Hi-Z
     c.set_mode(1, pysmu.Mode.HI_Z)  # CH B Hi-Z
     MainWindow.add_list_item(MainWindow, serials[i], i, c.start, c.stop)
 
-startGUI()
+
 
 # # Beispiel: Gerät 1 starten, Gerät 2 später starten/stoppen