# Buggy code
async def async_added_to_hass(self):
    """Store register state change callback."""
    try:
        if not self.enabled:
            return
    except AttributeError:
        pass
    # Register event handler on bus
    self._listener = self.hass.bus.async_listen(
        f"{ALEXA_DOMAIN}_{hide_email(self._login.email)}"[0:32], self._handle_event
    )


# Traceback (ValueError)
2019-10-26 14:43:05 ERROR (MainThread) [homeassistant.config_entries] Error setting up entry ***REDACTED*** - amazon.com for media_player
Traceback (most recent call last):
File "/usr/src/homeassistant/homeassistant/config_entries.py", line 190, in async_setup
hass, self
File "/usr/src/homeassistant/homeassistant/components/media_player/__init__.py", line 340, in async_setup_entry
return await hass.data[DOMAIN].async_setup_entry(entry)
File "/usr/src/homeassistant/homeassistant/helpers/entity_component.py", line 151, in async_setup_entry
raise ValueError("Config entry has already been setup!")
ValueError: Config entry has already been setup!
2019-10-26 14:43:05 ERROR (MainThread) [homeassistant.config_entries] Error setting up entry ***REDACTED*** - amazon.com for alarm_control_panel
Traceback (most recent call last):
File "/usr/src/homeassistant/homeassistant/config_entries.py", line 190, in async_setup
hass, self
File "/usr/src/homeassistant/homeassistant/components/alarm_control_panel/__init__.py", line 74, in async_setup_entry
return await hass.data[DOMAIN].async_setup_entry(entry)
File "/usr/src/homeassistant/homeassistant/helpers/entity_component.py", line 151, in async_setup_entry
raise ValueError("Config entry has already been setup!")
ValueError: Config entry has already been setup!
2019-10-26 14:43:05 ERROR (MainThread) [homeassistant.config_entries] Error setting up entry ***REDACTED*** - amazon.com for switch
Traceback (most recent call last):
File "/usr/src/homeassistant/homeassistant/config_entries.py", line 190, in async_setup
hass, self
File "/usr/src/homeassistant/homeassistant/components/switch/__init__.py", line 79, in async_setup_entry
return await hass.data[DOMAIN].async_setup_entry(entry)
File "/usr/src/homeassistant/homeassistant/helpers/entity_component.py", line 151, in async_setup_entry
raise ValueError("Config entry has already been setup!")
ValueError: Config entry has already been setup!
2019-10-26 14:43:05 ERROR (MainThread) [homeassistant.config_entries] Error setting up entry ***REDACTED*** - amazon.com for sensor
Traceback (most recent call last):
File "/usr/src/homeassistant/homeassistant/config_entries.py", line 190, in async_setup
hass, self
File "/usr/src/homeassistant/homeassistant/components/sensor/__init__.py", line 60, in async_setup_entry
return await hass.data[DOMAIN].async_setup_entry(entry)
File "/usr/src/homeassistant/homeassistant/helpers/entity_component.py", line 151, in async_setup_entry
raise ValueError("Config entry has already been setup!")
ValueError: Config entry has already been setup!**System details**```

# Fixed code
async def async_added_to_hass(self):
    """Store register state change callback."""
    try:
        if not self.enabled:
            return
    except AttributeError:
        pass
    # Register event handler on bus
    self._listener = async_dispatcher_connect(
        self.hass,
        f"{ALEXA_DOMAIN}_{hide_email(self._login.email)}"[0:32],
        self._handle_event,
    )