Error SQL Server attempt to attach an auto-named database
<p>I get this error:</p>

<blockquote>
  <p>An exception of type 'System.Data.SqlClient.SqlException' occurred in System.Data.dll but was not handled in user code</p>
  
  <p>Additional information: An attempt to attach an auto-named database for file C:\Program Files (x86)\IIS Express\DB Report.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC</p>
</blockquote>

<p>My config:</p>

<pre><code>&lt;connectionStrings&gt;
    &lt;add name="constr" 
         connectionString="data source=(LocalDB)\MSSQLLocalDB;attachdbfilename=&amp;quot;|DataDirectory|\DB Report.mdf&amp;quot;;integrated security=True;connect timeout=30;MultipleActiveResultSets=True;App=EntityFramework" 
         providerName="System.Data.SqlClient" /&gt;
&lt;/connectionStrings&gt;
</code></pre>

<p>Help me please .. I have problem a few day</p>