The entity type 'stream' requires a primary key to be defined. .Net Core 2.1

I'm Using .NET Core 2.1.1 with Entity Framework Core 2.1.1, and I have the following Entity:

Some Entity

using System;
using System.ComponentModel.DataAnnotations;
using System.IO;

namespace MyWebApp.Models
{
    public class Certificate
    {
        [Key]
        public int Id { get; set; }

        public DateTime CreatedAt { get; set; }

        public DateTime RequestedAt { get; set; }

        public Stream FileStream { get; set; }
    }
}

Which represents a Certificate object where I plan to store the FileStream of a PDF file, using the last property of course. But When I try either to run a Migration using EF Core's Package Manager console command Add-Migration Foo, or when I try to run the project using an in-memory DataBase, I get the following errors:

When trying to add a Role

The entity type 'stream' requires a primary key to be defined.

It only happens when the last property (FileStream) is present in the Entity, if I remove it works fine. I've searched other related questions, and most of them point to either:

• The primary key is not being recognized by EF because of naming conventions.
• A composite Key must be explicitly defined using the Fluent API.
• Just place a [Key] attribute before the primary key property.

I've also tried to define the primary key using the Fluent API:

Here is my DbContext:

using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore;
using System.IO;

namespace MyWebbApp.Models
{
public class DbContext : IdentityDbContext<IdentityUser>
{
    public DbSet<ActionValue> ActionValues { get; set; }
    public DbSet<Certificate> Certificates { get; set; }
    public DbSet<VisualIVR> VisualIVRs { get; set; }
    public DbSet<SMSRequest> SMSRequests { get; set; }

    public DbContext (DbContextOptions<VysContext> options)
        : base(options)
    {

    }

    protected override void OnModelCreating(ModelBuilder builder)
    {
        base.OnModelCreating(builder);

        builder.Entity<Certificate>()
            .HasKey(c => c.Id);
    }
}

Here are the complete exception details

System.AggregateException
  HResult=0x80131500
  Message=One or more errors occurred.
  Source=System.Private.CoreLib
  StackTrace:
   at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
   at System.Threading.Tasks.Task.Wait()
   at VysMiddleware.Startup.Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerfactory) in H:/MyApp/Startup.cs:line 84

Inner Exception 1:
AggregateException: One or more errors occurred.

Inner Exception 2:
InvalidOperationException: The entity type 'Stream' requires a primary key to be defined.

It seems to be something regarding the use of the Stream type, but I already have a primary key defined. Any suggestions?, Thanks so much for your help.

You can't store a file stream in your database currently with EF Core. You have a few options:

• Store the result of reading that file stream, which in the case of PDF file would be a byte[] blob. It's generally recommended not to store files in the database though.

• Store the path to the PDF file in your database. e.g. "Documents/Certificates/xxxx.pdf"

• If you don't need the PDF persisted in the database, then just tell EF to ignore it. This can be done by adding a NotMapped attribute to the property:

  public class Certificate
  {
      [Key]
      public int Id { get; set; }
  
      public DateTime CreatedAt { get; set; }
  
      public DateTime RequestedAt { get; set; }
  
      [NotMapped]
      public Stream FileStream { get; set; }
  }
  

  or in Fluent API:

  builder.Entity<Certificate>()
      .HasKey(c => c.Id)
      .Ignore(c => c.FileStream);