TypeError: getattr(): attribute name must be string

[dragorex71]

I use this addon with a Fujitsu air conditioner for years.
Recently i have experienced the disconnection of the device from home assistant: it was connected to wifi but for the addon it wasn't and i had to restart the addon for reconnect the air conditioner.
I have tried to reinstall the addon, manually deleting the old config_* file in hisense folder before the new installation.
Now i have the following problem:

Device AC000W002535674 has:
                              IP address: 192.168.xxxxxxx
                              lanip_key: xxxxxxxxxxxxxxxxxxxxxxxx
                              lanip_key_id: 13268


Traceback (most recent call last):
  File "/usr/local/lib/python3.10/runpy.py", line 196, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/usr/local/lib/python3.10/runpy.py", line 86, in _run_code
    exec(code, run_globals)
  File "/app/aircon/__main__.py", line 303, in <module>
    asyncio.run(run(parsed_args))
  File "/usr/local/lib/python3.10/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "/usr/local/lib/python3.10/asyncio/base_events.py", line 649, in run_until_complete
    return future.result()
  File "/app/aircon/__main__.py", line 251, in run
    await asyncio.gather(mqtt_loop(mqtt_client), setup_and_run_http_server(parsed_args, devices),
  File "/app/aircon/__main__.py", line 163, in mqtt_loop
    mqtt_client.loop()
  File "/usr/local/lib/python3.10/site-packages/paho_mqtt-1.6.1-py3.10.egg/paho/mqtt/client.py", line 1120, in loop
    return self._loop(timeout)
  File "/usr/local/lib/python3.10/site-packages/paho_mqtt-1.6.1-py3.10.egg/paho/mqtt/client.py", line 1164, in _loop
    rc = self.loop_read()
  File "/usr/local/lib/python3.10/site-packages/paho_mqtt-1.6.1-py3.10.egg/paho/mqtt/client.py", line 1556, in loop_read
    rc = self._packet_read()
  File "/usr/local/lib/python3.10/site-packages/paho_mqtt-1.6.1-py3.10.egg/paho/mqtt/client.py", line 2439, in _packet_read
    rc = self._packet_handle()
  File "/usr/local/lib/python3.10/site-packages/paho_mqtt-1.6.1-py3.10.egg/paho/mqtt/client.py", line 3039, in _packet_handle
    return self._handle_connack()
  File "/usr/local/lib/python3.10/site-packages/paho_mqtt-1.6.1-py3.10.egg/paho/mqtt/client.py", line 3138, in _handle_connack
    on_connect(
  File "/app/aircon/mqtt_client.py", line 33, in mqtt_on_connect
    device.get_property(prop_name),
  File "/app/aircon/aircon.py", line 109, in get_property
    return getattr(self._properties, name, None)
TypeError: getattr(): attribute name must be string

The ip address is correct
Can someone help me?
Thanks in advance