Display two table data in one

Question

Hi doing a master details and currently in the process of display two tables data based on invoice number but I have this error

An exception of type 'System.Data.Entity.Core.EntityCommandExecutionException' occurred in EntityFramework.SqlServer.dll but was not handled in user code 

{"Invalid column name 'klsm_Invoice_InternalInvoiceNo'.\r\nInvalid column name 'klsm_Invoice_InternalInvoiceNo'.\r\nInvalid column name 'klsm_Invoice_InternalInvoiceNo'."}

I am following Tutorial: Implement CRUD Functionality with the Entity Framework in ASP.NET MVC but I have come to a problem.

Desc class

[Table("klsm_InvoiceDesc")]
public class Desc
{
    [Key]
    public string InternalInvoiceNo { get; set; }
    
    public string InvoiceNo { get; set; }

    public int DescNo { get; set; }

    public string Principal { get; set; }

    public string ChargeCode { get; set; }

    public string Quantity { get; set; }

    public string Description { get; set; }

    public string UnitPrice { get; set; }

    public string Amount { get; set; }

    public string ForeignAmount { get; set; }

    public string EL1 { get; set; }

    public string EL2 { get; set; }

    public string ShortName { get; set; }

    public string InvoiceType { get; set; }

    public string PONumber { get; set; }

    public string Batch { get; set; }

    public string CCVBatch { get; set; }

    public string PaidAmount { get; set; }

    public string Paid { get; set; }

    public string TT { get; set; }

    public string BankCode { get; set; }

    //public string Id { get; set; }

    public virtual College klsm_Invoice{ get; set; }
}

College class

[Table("klsm_Invoice")]
public class College
{
    [Key]
    public string InternalInvoiceNo { get; set; }
    public string InvoiceNo { get; set; }
    public DateTime InvoiceDate { get; set; }

    public string CustomerName { get; set; }
    public int Year { get; set; }
    public int Month { get; set; }

    public decimal Amount { get; set; }
    public decimal ForeignAmount { get; set; }

    public string UserCreated { get; set; }

    public string UserModified { get; set; }
    public int AccMonth { get; set; }

    public int AccYear { get; set; }

    public string AccStatus { get; set; }

    public string Status { get; set; }

    public string PaidStatus { get; set; }

    public string Principal { get; set; }

    public DateTime DateCreated { get; set; }

    public DateTime DateModified { get; set; }

    public string EL1 { get; set; }

    public string InvoiceType { get; set; }

    public string CurrencyType { get; set; }

    public decimal ExchangeRate { get; set; }

    public string GSTChecked { get; set; }

    public DateTime PaymentSchedule { get; set; }

    public string PaymentMode { get; set; }

    public string CashAdvance { get; set; }

    public virtual ICollection<Desc> klsm_InvoiceDesc { get; set; }
    
}

Home Controller

public ActionResult Details(string id)
{

    College klsm_Invoice = db.klsm_Invoice.Find(id);
    
    return View(klsm_Invoice);
}