Temperature in room not working


#1

I have an issue with the following config

{
    "dashboards": {
        "home": {
            "columns": 10,
            "rows": 2,
            "pages": [
                {
                    "label": "Heizung",
                    "icon": "radiator",
                    "widgets": [
                        {
                            "type": "room",
                            "position": "0-0,2-2",
                            "properties": {
                                "label": "Wohnzimmer",
                                "photo": {
                                    "binding": "Living_Backdrop_Image"
                                },
                                "elements": {
                                    "temperature": {
                                        "type": "temperature",
                                        "icon": "temperature",
                                        "state": {
                                            "binding": "Living_Heating_Temperature_Value"
                                        }
                                    }
                                }
                            }
                        }
                    ]
                }
            ]
        }
    }
}

The corresponding Item looks like
Number Living_Heating_Temperature_Value "[%.1f]" { channel="..."}

When I load this into the app, I receive the well-known Unable to import <host> config error.
What is wrong about that? If I switch the type from temperature to switch, the error seems to be gone (though it doesn’t show the actual value of course). Also, If I remove the formatting part in the item definition from “%.1f” to “”, no error is shown.