Error when setting up RFXTRX sensor

I’ve just moved from using a Pi 3B to a Pi 4B. Unfortunately, I also upgraded HA to 110.1 at the same time, so I can’t be sure what causes this problem.

The RFXTRX hub is plugged into a USB2 socket (tried it in the USB3 socket with no difference). The config is:

rfxtrx:
  device: /dev/serial/by-id/usb-RFXCOM_RFXtrx433_A1XETXVE-if00-port0
  debug: true

I also have a package that includes the following:

sensor:
  - platform: rfxtrx
    automatic_add: true
    devices:
      "a520900d30002a61a0279":
        name: Shack Environment
        data_type:
          - Temperature
          - Humidity

I am seeing the following in the log but cannot see why.

Logger: homeassistant.components.sensor
Source: components/rfxtrx/sensor.py:52 
Integration: Sensor (documentation, issues) 
First occurred: 11:22:52 (1 occurrences) 
Last logged: 11:22:52

Error while setting up rfxtrx platform for sensor
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/helpers/entity_platform.py", line 178, in _async_setup_platform
    await asyncio.wait_for(asyncio.shield(task), SLOW_SETUP_MAX_WAIT)
  File "/usr/local/lib/python3.7/asyncio/tasks.py", line 442, in wait_for
    return fut.result()
  File "/usr/local/lib/python3.7/concurrent/futures/thread.py", line 57, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/usr/src/homeassistant/homeassistant/components/rfxtrx/sensor.py", line 52, in setup_platform
    device_id = "sensor_{}".format(slugify(event.device.id_string.lower()))
AttributeError: 'NoneType' object has no attribute 'device'

Curiouser and curiouser.
In an attempt to isolate the problem, I deliberately corrupted the device ID for the hub. HA should have barfed with an Error about device not found, but the log says rfxtrx was configured in 0.2 secs and there are no errors in the log.

Not sure that would throw an error, it’s just that you won’t receive anything if you have no device with this ID.
The RFX will only provide information once it receives data from the said device. It does not hold states…

Hmm, OK.
I would generally expect software to object if you gave it incorrect info, rather than just ignore it. Obviously not in this case.

This still doesn’t get me any closer to understanding why I’m not getting any rfxtrx traffic since I moved to a Pi4 though.

Are you using home assistant OS, or an alternative OS ( raspbian, ubuntu , …) ?

it’s not incorrect info. It’s like sending a letter to the wrong address. The address itself is not incorrect, it’s just not the one where your friend lives
Checking against my config, the only difference is that my device id is not enclosed in quotes…
Though I somehow doubt that’s what it is…

@francisp I’m running Hassio Supervised (I think that’s what it is called). i.e. Hassio_supervisor running on my own Docker environment: exactly as it’s been before.

Ssh to the host (not the HA container) and run this command :

apt-get purge modemmanager

Nice thought, @francisp. I had forgotten about other services using serial devices. In this case, modem manager is not installed, but I’m going to do some digging to see if maybe something else is.