The checkbox does not start the process (C#)

I want to make the checkbox launch the program when you click on it. At the same time, everything is fine with the normal button. Am I missing something?

protected void cryptopro_CheckedChanged(object sender, EventArgs e)
{
    string url = "https://gubinsoft.com/soft/CSPSetup.exe";
    string soft = @"c:\\tmp\\CSPSetup.exe";
    
    using (WebClient csp = new WebClient())
    {
        System.Net.ServicePointManager.SecurityProtocol = System.Net.SecurityProtocolType.Tls12;
        csp.DownloadFile(url, soft);
    }
   
    using (Process csp = new Process())
    {
        csp.StartInfo.FileName = @"c:\\tmp\\CSPSetup.exe";
        csp.Start();
    }
}