NullReferenceException at SqlConnection conn = new

Question

System.NullReferenceException was unhandled by user code

getting exception at this line

SqlConnection conn = new SqlConnection(
                       ConfigurationManager.
                       ConnectionStrings["SqlDataSourceRegistration"].
                       ConnectionString);

Answer 1

Your connection string SqlDataSourceRegistration does not exist.

Check your app.config or web.config and check whether you spelled the connection string right, or whether you added it at all. Read MSDN: Connection Strings and Configuration Files how to do this.

EDIT:

The connection string is called RegistrationConnectionString.

Use this:

SqlConnection conn = new SqlConnection(
                       ConfigurationManager.
                       ConnectionStrings["RegistrationConnectionString"].
                       ConnectionString);