Is it ok for platform code to raise Exceptions?

Hi!

I have a sensor (pyload) which raises a Timeout-Exception on startup, if my NAS is not online. The result is that the sensor is skipped and won’t come back, once my NAS is online. Shouldn’t the sensor just report that it is ‘offline’ until the server is found? If this is not by design, is there a way to restart the initialization of the sensor?

Here is the Exception:

2017-12-12 12:33:57 ERROR (Thread-5) [homeassistant.components.sensor.pyload] Error setting up pyLoad API: HTTPConnectionPool(host='ono-sendai-filer', port=8001): Max retries exceeded with url: /api/login (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x6cf7f890>: Failed to establish a new connection: [Errno 113] No route to host',))

p.s. I suppose this is a platform-code bug, which is why I ask here. Sorry if this is supposed to go into a different category!