System.Disagnostics.Process.Start Error

System.Diagnostics.Process.Start(@""+ BASE_DIR + "Checker" +Path.DirectorySeparatorChar+ "Checker.exe", "-a");

var startInfo = new ProcessStartInfo {
    FileName = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, @"Checker\Checker.exe"),
    Arguments = "-a",
};
startInfo.WorkingDirectory = Path.GetDirectoryName(startInfo.FileName);
Process.Start(startInfo);

using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())

// POST [url]https://*****.com/cas/tgts[/url]
            {
                data = "{\"login\":\"" + sUsername + "\",\"password\":\"" + sPassword + "\"}";
                ByteArr = Encoding.ASCII.GetBytes(data);
                {
                    HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://*****.com/cas/tgts");
                    request.Method = "POST";
                    request.CookieContainer = Cook;
                    request.ContentType = "application/json; charset=utf-8";
                    request.ContentLength = ByteArr.Length;
                    request.GetRequestStream().Write(ByteArr, 0, ByteArr.Length);
                    using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
                        using (StreamReader myStreamReader = new StreamReader(response.GetResponseStream(), Encoding.UTF8))
                        {
                            html = myStreamReader.ReadToEnd();
                            json = JObject.Parse(html);
....
                        }
                    }
                }
            }
                    {

var startInfo = new ProcessStartInfo
                {
                    FileName = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, @"Checker\Checker.exe"),
                    Arguments = "-a, uname ..., password ... ",
                };
                startInfo.WorkingDirectory = Path.GetDirectoryName(startInfo.FileName);
                Process.Start(startInfo);

string configPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, @"config.ini");