The connection string 'MyConnection' in the application's configuration file does not contain the required providerName attribute."

You're missing the following piece of code after the connectionString attribute (assuming that you're using SQL):

providerName="System.Data.SqlClient"

Sometime in the future. the complete code

<add name="YouContext" connectionString="Integrated Security=True;Persist Security Info=False;Initial Catalog=YourDatabaseName;Data Source=YourPCName;" providerName="System.Data.SqlClient"/>