[Solved] The relationship model was not loaded because the type model is not available.The following information may be useful in resolving the previous error: The required property does not exist on the type model class

When I created new table “post” and give foreign key relation to another “category” table after that run the custom tool by right click on edmx file. While running the application I got the following error. It was resolved by including post table foreign key relation to the category class.  

The relationship model was not loaded because the type model is not available.The following information may be useful in resolving the previous error:
The required property does not exist on the type model class

Example:

namespace example.Areas.Admin.Models
{
    using System;
    using System.Collections.Generic;
    public partial class Category
    {
        public Category()
        {
            this.Posts = new HashSet<Post>();
        }
        public int CategoryId { get; set; }
        public string Name { get; set; }
        public string Description { get; set; }
        public Nullable<int> CreatedUserId { get; set; }
        public Nullable<System.DateTime> PostedOn { get; set; }
        public Nullable<System.DateTime> ModifiedOn { get; set; }
        public Nullable<int> ModifiedUserId { get; set; }
        public virtual ICollection<Post> Posts { get; set; }
    }
}

if we given any foregin key relation to the table and also entity is not updated properly. Manually we need to set the model class  property or function.