Answer by dbc for Discarding garbage characters after json object with Json.Net

You can also set JsonSerializerSettings.CheckAdditionalContent = false to tell the serializer to ignore any content after the end of the deserialized JSON object:

var result = JsonConvert.DeserializeObject<Dictionary<string, long>>(json, new JsonSerializerSettings { CheckAdditionalContent = false })

Oddly enough it is necessary to do this explicitly despite the fact that the default value seems to be false already, since the underlying field is nullable.