This is a long outstanding issue and despite earlier post no resolution.
Synology DSM integration starting failing after first HA Core update to 2023.2.1.
When stopping surveillance system on Synology DS the HA Integration works, switching it back on it fails…
Fault: Retrying setup: ‘utf-8’ codec can’t decode byte 0x8b in position 40: invalid start byte
Hope someone has an idea as it is quite frustrating that i cant get it to work 
Thanks, Mario
2025-05-05 22:35:55.274 ERROR (MainThread) [homeassistant.components.synology_dsm.coordinator] Unexpected error fetching NAS_Fritz SynologyDSMSwitchUpdateCoordinator data
Traceback (most recent call last):
File “/usr/src/homeassistant/homeassistant/helpers/update_coordinator.py”, line 380, in _async_refresh
self.data = await self._async_update_data()
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File “/usr/src/homeassistant/homeassistant/components/synology_dsm/coordinator.py”, line 54, in _async_wrap
return await func(self, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File “/usr/src/homeassistant/homeassistant/components/synology_dsm/coordinator.py”, line 123, in _async_update_data
“home_mode”: bool(await surveillance_station.get_home_mode_status())
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File “/usr/local/lib/python3.13/site-packages/synology_dsm/api/surveillance_station/init.py”, line 257, in get_home_mode_status
raw_data = await self._dsm.get(self.HOME_MODE_API_KEY, “GetInfo”)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File “/usr/local/lib/python3.13/site-packages/synology_dsm/synology_dsm.py”, line 251, in get
return await self._request(“GET”, api, method, params, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File “/usr/local/lib/python3.13/site-packages/synology_dsm/synology_dsm.py”, line 330, in _request
response = await self._execute_request(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
request_method, url, params, raw_response_content, **kwargs
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
)
^
File “/usr/local/lib/python3.13/site-packages/synology_dsm/synology_dsm.py”, line 451, in _execute_request
return dict(await response.json(content_type=content_type))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File “/usr/src/homeassistant/homeassistant/helpers/aiohttp_client.py”, line 83, in json
return await super().json(*args, loads=loads, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File “/usr/local/lib/python3.13/site-packages/aiohttp/client_reqrep.py”, line 1298, in json
return loads(stripped.decode(encoding))
~~~~~~~~~~~~~~~^^^^^^^^^^
UnicodeDecodeError: ‘utf-8’ codec can’t decode byte 0x8b in position 40: invalid start byte