If you have this logo on the back of the ECU-R your firmware will be ECU-R-Pro
The query it executes delivers an unexpected empty response from the ECU which is misinterpreted and an error is raised. There is no cached data available yet so the integration fails. Try powercycle the ECU to see if this solves the issue. It is still a mistery why the ECU-R-Pro has this issue but work to bypass this using a HTTP call to the webinterface on the ECU-R-Pro is in progress. It could also be a timeout on the receiving part because this has not been tried yet. If you know how to edit APSystemsSocket.py you could try (only) adding self.sock.settimeout(self.timeout) at the locations pointed in Use timeout on send and receive · Discussion #50 · ksheumaker/homeassistant-apsystems_ecur · GitHub restart HA after editting. For ECU-R and ECU-B owners there is no issue with the integration. Please let us know what the results are so we can rule out this option.