JsonConvert.SerializeObject,json转换object错误这怎么办

Self referencing loop detected for property 'xxxx' with type 'System.Data.Entity.DynamicProxies.XXX_XXX'. Newtonsoft. Json.JsonSerializationException JsonConvert.SerializeObject(arg, Formatting.None, new JsonSerializerSettings() { ReferenceLoopHandling = ReferenceLoopHandling.Ignore });