--- a/src/eric7/MicroPython/MicroPythonWidget.py	Thu Mar 16 12:03:23 2023 +0100
+++ b/src/eric7/MicroPython/MicroPythonWidget.py	Thu Mar 16 12:03:59 2023 +0100
@@ -1243,7 +1243,7 @@
         """
         Private method to disconnect from the device.
         """
-        self.__device.setConnected(False)
+        self.__device and self.__device.setConnected(False)
         self.__interface.disconnectFromDevice()
         self.__setConnected(False)