.Net Core 3.0 possible object cycle was detected which is not supported

Question

I have 2 entities that are related as one to many

public class Restaurant {
   public int RestaurantId {get;set;}
   public string Name {get;set;}
   public          


        

Answer 1

Who are still facing this issue: check if you await-ed all async methods.

Answer 2

I have tried your code in a new project and the second way seems to work well after installing the package Microsoft.AspNetCore.Mvc.NewtonsoftJson firstly for 3.0

services.AddControllersWithViews()
    .AddNewtonsoftJson(options =>
    options.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore
);

Try with a new project and compare the differences.