Error openning a connection

Here is the error: A connection was successfully established with the server, but then an error occurred during the login process, error 0, No process is on the other end of the pipe. What cause this error and how do I fix it?

SQL Server 2016

Visual Studio 2017

Here is my connection string:

string connectionString = @"Data Source=BRENTHUMBER\BRENT;Initial Catalog=BrentPractice;Integrated Security=False";
            SqlConnection conn = new SqlConnection(connectionString);
            SqlCommand cmd = new SqlCommand();
            try
            {
                string strCommand = "Insert INTO Tracker(id, edi, personsName, date, descriptor, details, reasons, notes)";
                cmd.CommandType = CommandType.Text;
                cmd.CommandText = strCommand;
                cmd.Connection = conn;
                conn.Open(); // <-----------------------------------------error here