title: Error updating packages in vb 2019 community for macos for asp.net core mvc application
body: <p>installing my previously run booshop application from windows on visual basic for macos, but unable t update "system.web.entity", "mysql.data", "mysql.data.entity.ef6".
  i am very beginner in asp.net so not sure what I am doing wrong here and how to modify this.
  If anyone came across same issues with VB for macos, please share your insights on how to correct it.</p>
  
  <p>Error1:
  /Users/lakhanpals/Downloads/BookstoreASPMVC-master/Bookstore/Models/IdentityModels.cs(33,33): Error CS0246: The type or namespace name 'MySql' could not be found (are you missing a using directive or an assembly reference?) (CS0246) (Bookstore)</p>
  
  <p>Error2:
  /Users/lakhanpals/Downloads/BookstoreASPMVC-master/Bookstore/Models/BookstoreContext.cs(33,33): Error CS0246: The type or namespace name 'MySql' could not be found (are you missing a using directive or an assembly reference?) (CS0246) (Bookstore)</p>
  
  <p>warning1:</p>
  
  <p>/Library/Frameworks/Mono.framework/Versions/6.0.0/lib/mono/msbuild/Current/bin/Microsoft.Common.CurrentVersion.targets(5,5): Warning MSB3245: Could not resolve this reference. Could not locate the assembly "System.Web.Entity". Check to make sure the assembly exists on disk. If this reference is required by your code, you may get compilation errors. (MSB3245) (Bookstore)</p>
  
  <p>warning2:
  /Library/Frameworks/Mono.framework/Versions/6.0.0/lib/mono/msbuild/Current/bin/Microsoft.Common.CurrentVersion.targets(5,5): Warning MSB3245: Could not resolve this reference. Could not locate the assembly "MySql.Data.Entity.EF6". Check to make sure the assembly exists on disk. If this reference is required by your code, you may get compilation errors. (MSB3245) (Bookstore)</p>
  
  <p>warning3:
  /Library/Frameworks/Mono.framework/Versions/6.0.0/lib/mono/msbuild/Current/bin/Microsoft.Common.CurrentVersion.targets(5,5): Warning MSB3245: Could not resolve this reference. Could not locate the assembly "MySql.Data". Check to make sure the assembly exists on disk. If this reference is required by your code, you may get compilation errors. (MSB3245) (Bookstore)</p>
  
  <p>in One of the Models- BookstoreContect.cs</p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.Data.Entity;
  using System.Data.Entity.Validation;
  using System.Linq;
  using System.Web;
  using Bookstore.Library;
  using System.ComponentModel.DataAnnotations.Schema;
  using System.ComponentModel.DataAnnotations;
  
  namespace Bookstore.Models
  {
      [DbConfigurationType (typeof 
      (MySql.Data.Entity.MySqlEFConfiguration))]
      public class BookstoreContext: DbContext
      {
          public BookstoreContext()
              : base(Db.ConString)
          {
              Database.SetInitializer(new 
              CreateDatabaseIfNotExists&lt;BookstoreContext&gt;());
          }
          protected override void OnModelCreating(DbModelBuilder 
          modelBuilder)
          {
              base.OnModelCreating(modelBuilder);
          }
          public DbSet&lt;Book&gt;Books{get; set;}
          public DbSet&lt;Publisher&gt; Publishers { get; set; }
      }
      [Table("books")]
      public class Book
      {
          [Key]
          [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
          public int BookId { get; set; }
  
          [Required(ErrorMessage = "Please enter the name of the book.")]
          [MaxLength(50, ErrorMessage = "Name too long. Max 50 characters")]
          public string BookName { get; set; }
  
          [Required]
          public DateTime DatePublished { get; set; }
  
          [Required(ErrorMessage = "Please choose publisher for the book.")]
          public int PublisherId { get; set; }
          public Publisher publisher { get; set; }
      }
  
      [Table("publishers")]
      public class Publisher
      {
          [Key]
          [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
          public int PublisherId { get; set; }
  
          [MaxLength(50, ErrorMessage = "Name too long. Max 50 characters")]
          [Required(ErrorMessage = "Please enter the name of the publisher.")]
          public string PublisherName { get; set; }
  
          [Required]
          [MaxLength(25, ErrorMessage = "Email too long! Max 25 characters")]
          [EmailAddress(ErrorMessage = "Enter a valid e-mail address")]
          public string PublisherEmail { get; set; }
  
          [Required]
          [MaxLength(20, ErrorMessage = "Phonenumber too long! Max 20 
  characters")]
          public string PublisherPhoneNumber { get; set; }
      }
  }
  </code></pre>
  
  <p>In Models-BookViewModel.cs</p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.Linq;
  using System.Web;
  
  namespace Bookstore.Models
  {
      public class BookViewModel
  
      {
          public int BookId { get; set; }
          public string BookName { get; set; }
          public DateTime DatePublished { get; set; }
          public string PublisherName { get; set; }
      }
  }
  </code></pre>