asp.net – 不支持每种类型的多个对象集.对象集’ApplicationUse

我正在学习MVC 5,几乎所有内容都是由内置模板创建的.
我只添加了一个类历史

public class History
{
    [Key]
    public DateTime Date { get; set; }

    public virtual ApplicationUser User { get; set; }

    public string ItemName { get; set; }

}

在内置的ApplicationUser中：

public class ApplicationUser : IdentityUser
    {
        public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<ApplicationUser> manager)
        {
            // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
            var userIdentity = await manager.CreateIdentityAsync(this,DefaultAuthenticationTypes.ApplicationCookie);
            // Add custom user claims here
            return userIdentity;
        }

        public virtual ICollection<History> Histories { get; set; }
    }

这是错误消息：

Multiple object sets per type are not supported. The object sets 'ApplicationUsers' and 'Users' can both contain instances of type 'MyOnlineShopping.Models.ApplicationUser'.

    Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

    Exception Details: System.InvalidOperationException: Multiple object sets per type are not supported. The object sets 'ApplicationUsers' and 'Users' can both contain instances of type 'MyOnlineShopping.Models.ApplicationUser'.

    Source Error: 


    Line 124:            {
    Line 125:                var user = new ApplicationUser() { UserName = model.Email,Email = model.Email };
    Line 126:                IdentityResult result = await UserManager.CreateAsync(user,model.Password);
    Line 127:                if (result.Succeeded)
    Line 128:                {
Source File: f:WorkplaceMyOnlineShoppingMyOnlineShoppingControllersAccountController.cs    Line: 126