EF: Unrecognized element 'providers' exception while downgrading from EF-6 to EF-5

Sometimes the "<providers>" configuration is not removed while downgrading from EF-6 to EF-5.
some simply remove these "<providers>" tags inside the <entityFramework> tag.

<entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
      <parameters>
        <parameter value="v12.0" />
      </parameters>
    </defaultConnectionFactory>
    <!--<providers>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
    </providers>-->
  </entityFramework>

Posted in: ENTITY FRAMEWORK