title: Unrecognized element in connection string
body: <p>Can't find what is wrong with my connection string:</p>
  
  <p>I get this exception:</p>
  
  <blockquote>
    <p>System.Configuration.ConfigurationErrorsException: Configuration system failed to initialize ---> System.Configuration.ConfigurationErrorsException: Unrecognized element. (D:\C#\learncsharp\Data access\AsyncSQL\AsyncSQL\bin\Debug\AsyncSQL.exe.Config line 2)</p>
  </blockquote>
  
  <p>This is my code:</p>
  
  <pre><code>string connectionString = null;
  string MovieDBContext = null;
  
  try
  {
      MovieDBContext = ConfigurationManager.ConnectionStrings["MovieDBContext"].ConnectionString;
      connectionString = ConfigurationManager.ConnectionStrings["ProgrammingInCSharpConnection"].ConnectionString;
  }
  catch (Exception e)
  {
      Console.WriteLine( e.ToString() );
  }
  </code></pre>
  
  <p>App.config:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8" ?&gt;
  &lt;configuration&gt;
      &lt;connectionStrings&gt;
          &lt;add name="MovieDBContext"
               connectionString="Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\Movies.mdf;Integrated Security=True"
               providerName="System.Data.SqlClient" /&gt;
          &lt;add name="ProgrammingInCSharpConnection" 
               connectionString="Data Source=(localdb)\v11.0;Initial Catalog=ProgrammingInCSharp;"
               providerName="System.Data.SqlClient" /&gt;
      &lt;/connectionStrings&gt;
      &lt;startup&gt; 
          &lt;supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.2" /&gt;
      &lt;/startup&gt;
  &lt;/configuration&gt;
  </code></pre>
  
  <p>What is wrong? And how to get details which element is wrong?</p>