Add identity into an ASP.NET Core 2.1 MVC project and maintain full control of the Identity UI

To maintain full control over the Identity UI in an ASP.NET Core 2.1 MVC project, scaffold the identity using the Windows version of Visual Studio 2017.

Scaffold the Identity

  1. Right click the web application project and select Add, New Scaffolded Item
  2. On the left side of the Add Scaffold dialog select Identity, and click the Add button
  3. Select your existing Layout page, so the scaffolding will not overwrite it
  4. Select the Identity functions (files) you want to override, and click the down arrow to select your existing data context class
  5. The MY_SOLUTION\MY_WEBAPP\ScaffoldingReadme.txt file contains tasks to do to set up the Identity UI. Based on that
    1. Add the following lines to the Configure method of the Startup.cs file in this order. If a line is already in the file, make sure the order is correct.
    2. Add to the ConfigureServices method of the Startup.cs file, if the line is not there.
  6. The Aeras, Identity, Pages, Account folder contains the .cshtml files you can modify.
  7. The code is in the .cshtml.cs file

Use your own SMTP server

To configure Identity to use you own SMTP server to send the Forgot my password and email verification emails, register a custom email sender.

  1. Add to the ConfigureServices method of the Startup.cs file
    // using Microsoft.AspNetCore.Identity.UI.Services;
    services.AddSingleton<IEmailSender, EmailSender>();
  2. Create the EmailSender class in the web application project
    // using Microsoft.AspNetCore.Identity.UI.Services;
    // using System.Threading.Tasks;
    public class EmailSender : IEmailSender
        public Task SendEmailAsync(string sTo, string sSubject, string sMessage)
            MyMessagingClass messaging = new MyMessagingClass();
            // Send an email message with SMTP
            messaging.MySendEmailMethod(sTo, sSubject, sMessage);
            return Task.CompletedTask;

For more information see



Error unprotecting the session cookie in an ASP.NET Core MVC application.

The new ASP.NET Core MVC framework automatically displays a message for the user to accept the application’s privacy policy. The default message is “Use this space to summarize your privacy and cookie use policy.” No cookies are saved in the user’s browser until they click the Accept button.

Even after accepting the terms, if the browser contains old, stale cookies the application may not be able to save cookies. The log contains

warn: Microsoft.AspNetCore.Session.SessionMiddleware[7]
Error unprotecting the session cookie.
System.Security.Cryptography.CryptographicException: The key … was not found in the key ring.

If the web application works in a new incognito window, clear the old cookies in your browser.

In Google Chrome

  1. In the Chrome menu select Clear Browsing Data
  2. On the Clear browsing data page select All time, and Cookies and other site data



Set the environment for an ASP.NET Core MVC web application

When the ASP.NET Core MVC web application starts, reads the name of the environment for an environment variable of the host computer. The compiled application contains the configuration for all supported environments, making possible to build and deploy the same artifact in every environment.

If the ASPNETCORE_ENVIRONMENT environment variable is not defined, the Production environment settings are loaded.

In Visual Studio the web application project sets the value on the Debug tab.

To set the environment on the server


To set the value globally that is preserved after restart

Command prompt

  1. Open the command prompt window and execute
    setx ASPNETCORE_ENVIRONMENT Development /M


  1. Open a PowerShell window and execute
    [Environment]::SetEnvironmentVariable("ASPNETCORE_ENVIRONMENT", "Development", "Machine")


  1. Add to the .bashrc or .bash_profile file
    export ASPNETCORE_ENVIRONMENT=Development


Configure the ASP.NET Core MVC web application

Create the environment-specific appsettings.json files

  1. In the web application project click the arrow next to the appsettings.json file to reveal the Development configuration file
  2. Right-click the appsettings.Development.json file and select Copy

  3. Right click the web application project and select Paste

  4. Rename the appsettings – Copy.Development.json file to appsettings.Production.json

  5. The file will automatically move under the appsettings.json file

Edit the configuration files

  1. Open the appsettings.Production.json file and add the connection string
        "ConnectionStrings": {
            "DefaultConnection": "Server=MY_DATABASE_URL;Database=MY_DATABASE_NAME;Username=MY_USERNAME;Password=MY_PASSWORD"


Procedure or function ‘`…_Insert`’ cannot be found in database …

When you use the Microsoft .NET Entity framework to access a MySql database, the autogenerated code throws an error when you try to insert a row into the database with


Server Error in ‘/’ Application.
Procedure or function ‘`…_Insert`’ cannot be found in database ‘`…`’.
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: MySql.Data.MySqlClient.MySqlException: Procedure or function ‘`…_Insert`’ cannot be found in database ‘`…`’.

The auto-generated class tries to use stored procedures to update the database. To use the Entity Framework Linq commands, comment out the line that contains “MapToStoredProcedures”

 protected override void OnModelCreating(DbModelBuilder modelBuilder)
     // modelBuilder.Entity<twitter_keywords>().MapToStoredProcedures();



No connection string named ‘…’ could be found in the application config file.

Two-tier applications separate the presentation layer and the data layer, and all database access related objects are located in the data-tier.

When the application runs, the config file of the main project is read. In web applications, it is the web.config, in console applications the app.config file.

When you get the following runtime exception

Exception thrown: ‘System.InvalidOperationException’ in EntityFramework.dll
An exception of type ‘System.InvalidOperationException’ occurred in EntityFramework.dll but was not handled in user code
No connection string named ‘…Entities’ could be found in the application config file.


  1. Copy the connection string from the app.config file of the data-tier to the main project’s config file.
 <add name="USC_SocialMediaMSSQLEntities" connectionString="metadata=res://*/USC_SocialMedia_MSSQL.csdl|res://*/USC_SocialMedia_MSSQL.ssdl|res://*/USC_SocialMedia_MSSQL.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=MY_SERVER;initial catalog=MY_DATABASE;user id=MY_USER;password=MY_PASWORD;MultipleActiveResultSets=True;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />

2. This is a sample data access class in the data-layer to read data from the aspNetRoles table.

using System.Data.Entity;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SocialMedia_Data {
	public class SocialMediaData {

		private USC_SocialMediaMSSQLEntities _web;

		public SocialMediaData() {

			// Set up the database connections
			_web = new USC_SocialMediaMSSQLEntities();


		/// Returns the list of Roles
		public List GetRoles() {

			IEnumerable foundRoles = from aspNetRoles in _web.AspNetRoles
						 orderby aspNetRoles.DisplayOrder
						 select aspNetRoles;

			if (null == foundRoles || 0 == foundRoles.Count()) {
				return null;

			return foundRoles.ToList();


NotSupportedException: Unable to determine the provider name for provider factory of type ‘MySql.Data.MySqlClient.MySqlClientFactory’. Make sure that the ADO.NET provider is installed or registered in the application config

In a two-tier web application, the data layer is in a separate project. This allows better separation between the presentation layer and the data layer. This way you can reuse the data project in another application that targets the same database.

To access a MySql database you need to add the MySql.Data and MySql.Data.Entity NuGet packages to the data project.

When you develop a two-tier application that targets a MySql database you may get the runtime error

NotSupportedException: Unable to determine the provider name for provider factory of type ‘MySql.Data.MySqlClient.MySqlClientFactory’. Make sure that the ADO.NET provider is installed or registered in the application config.

Even if all database interaction is handled in the data project, and you added the MySql NuGet packages to it, you need to add the MySql.Data and MySql.Data.Entity NuGet packages to the web project too, because the Web.config file contains the connection string that includes the reference to MySql.Data.MySqlClient.

<add name="MY_CONNECTION_NAME" providerName="MySql.Data.MySqlClient" connectionString="server=localhost;port=3306;database=MY_DATABASE;uid=MY_USERNAME;password=MY_PASSWORD" />

At the time of writing do not use version of the packages, it causes the error

Exception thrown: ‘System.TypeLoadException’ in mscorlib.dll
An exception of type ‘System.TypeLoadException’ occurred in mscorlib.dll but was not handled in user code
Inheritance security rules violated by type: ‘MySql.Data.MySqlClient.MySqlProviderServices’. Derived types must either match the security accessibility of the base type or be less accessible.

Until a new, corrected version is published, install version of both packages in both projects.

For more information on how to connect to a MySql database from Visual Studio see Connect to a MySQL database from Visual Studio 2017



Create an ASP.NET MVC 5 Web Application with user authentication

To create a new ASP .NET MVC web application that contains user authentication code

  1. In the File menu of Visual Studio select New, Project
  2. On the left select Visual C#, Web, and in the middle select ASP.NET Web Application (.NET Framework)
  3. Enter the Name, select the solution folder location and click OK. The solution name will automatically match the value of the Name field.
  4. Select MVC and click the Change Authentication button
  5. To use your database for authentication select Individual User Accounts
  6. Make sure the correct authentication is selected and click OK

This ASP.NET MVC 5 web application automatically creates an SQL Express internal database in the App_Data directory of the application when you register the first user.

  1. Start the application
  2. Click Register in the menu of the web application
  3. Register a user

To use an external database for user authentication, see the next post at Configure the ASP.NET MVC 5 web application to use an external database for user authentication

The given assembly name or codebase was invalid. (Exception from HRESULT: 0x80131047)

When I made changes to the web.config file of an ASP.Net C# application, I have accidentally deleted a comma, and I started to get the runtime error message:

The given assembly name or codebase was invalid. (Exception from HRESULT: 0x80131047)

Make sure all necessary commas are there in the config files, Visual Studio does not check the format of those lines. In my case, the error was in

<provider invariantName="MySql.Data.MySqlClient" type="MySql.Data.MySqlClient.MySqlProviderServices, MySql.Data.Entity.EF6, Version=, Culture=neutral, PublicKeyToken=c5687fc88969c44d" />

Connect to a MySQL database from Visual Studio 2017

As of today weI can connect to a MySQL database, but cannot generate the Entity Data Model from a MySQL database in Visual Studio 2017

To access a MySQL database from Visual Studio 2017

IMPORTANT: First install MySQL for Visual Studio, and after that install MySQL Connector/Net.

If MySQL Connector/Net is already installed on your workstation, uninstall it before installing MySQL for Visual Studio and reinstall MySQL Connector/Net.

Install MySQL for Visual Studio

Available version information is at

  1. Close all instances of Visual Studio,
  2. Download the installer from
  3. Start the installer
  4. Click the Complete button,
  5. If you select Typical, make sure the Visual Studio 2017 components are selected


Install the MySql Connector/Net the fully-managed ADO.NET driver for MySQL

  1. Download the installer from
  2. Download version 6.9.10, because version 6.10.5 throws the

    Inheritance security rules violated by type: ‘MySql.Data.Entity.MySqlEFConfiguration’. Derived types must either match the security accessibility of the base type or be less accessible

    error. More info at

  3. Select version 6.9.10, your operating system and click the Download button
  4. If you don’t want to create an Oracle account, click the No thanks… link
  5. Start the downloaded installer
  6. Click the Complete button

Install the NuGet packages

Make sure to install the same version of the NuGet packages as the MySql Connector/Net