gistfile1.cs

[HttpPost]
public ActionResult Edit(int id, MyNameEntity name)
{
	if(!ModelState.IsValid)
	{
		return View(name);
	}
	return RedirectToAction("Index");
}
		
		
		
		
		
using System.ComponentModel.DataAnnotations;

namespace MyProject.Web.Models.Entities
{
    public class MyNameEntity
    {
        public int Id { get; set; }

        [Required]
        public string Name { get; set; }

        [Required]
        public NameGroup? Group { get; set; }

        [Required]
        public string Prop1 { get; set; }

        public string Prop2 { get; set; }
    }
}

When I renamed "name" to "test" it didn't return null anymore.

    [HttpPost]
    public ActionResult Edit(int id, MyNameEntity test)
    {
        if (!ModelState.IsValid)
        {
            return View(test);
        }
        return RedirectToAction("Index");
    }

    public ActionResult Edit(int id)
    {
        return View();
    }