home-assistant/core · warning · UpdateFailed

Connection to Pro unit lost: {err}

Error message

Connection to Pro unit lost: {err}

What it means

UpdateFailed raised when the Samba connection to the AirVisual Pro unit drops mid-operation (NodeConnectionError). Distinctively, the coordinator also schedules a one-shot config entry reload in the background (guarded by reload_task being None) to re-establish the connection, so this error both marks the update failed and triggers self-healing.

Source

Thrown at homeassistant/components/airvisual_pro/coordinator.py:74

        self.reload_task: asyncio.Task[bool] | None = None

    @override
    async def _async_update_data(self) -> dict[str, Any]:
        """Get data from the device."""
        try:
            data = await self._node.async_get_latest_measurements()
            data["history"] = {}
            if data["settings"].get("follow_mode") == "device":
                history = await self._node.async_get_history(include_trends=False)
                data["history"] = history.get("measurements", [])[-1]
        except InvalidAuthenticationError as err:
            raise ConfigEntryAuthFailed("Invalid Samba password") from err
        except NodeConnectionError as err:
            if self.reload_task is None:
                self.reload_task = self.hass.async_create_task(
                    self.hass.config_entries.async_reload(self.config_entry.entry_id)
                )
            raise UpdateFailed(f"Connection to Pro unit lost: {err}") from err
        except NodeProError as err:
            raise UpdateFailed(f"Error while retrieving data: {err}") from err

        return data

View on GitHub (pinned to 58a3fdb3ea)

Solutions

1. Confirm the Pro unit is powered on and its web dashboard loads.
2. Fix the unit's IP with a DHCP reservation or correct the config entry host.
3. Let the automatic reload task run — it re-establishes the session without user action.
4. Check network stability between Home Assistant and the unit if drops recur.
5. Shorten the update interval if SMB idle timeouts are disconnecting the session.

def is_airvisual_pro_connection_lost(err: Exception) -> bool:
    return isinstance(err, UpdateFailed) and str(err).startswith("Connection to Pro unit lost")

try:
    await coordinator.async_refresh()
except UpdateFailed as err:
    if str(err).startswith("Connection to Pro unit lost"):
        # coordinator already schedules a self-reload; just wait for the next cycle
        pass
    raise

When it happens

Trigger: async_get_latest_measurements() or async_get_history() raises NodeConnectionError: unit powered off, network drop to the unit, SMB session terminated by the device (idle timeout, reboot), or unit IP changed so the connection target is stale.

Common situations: Pro unit rebooting or power-cycled, WiFi instability, DHCP address change making the stored connection invalid, or long gaps between polls exceeding the unit's SMB session timeout.

Related errors

• Invalid Samba password
• Error while retrieving data: {err}
• Credential is already linked to a user
• Unable find multi-factor auth module: {mfa_module_id}
• update_error

AI-assisted analysis of home-assistant/core@58a3fdb3ea (2026-08-14). Data as JSON: /api/errors/7af885c24119442f. Report an issue: GitHub.