EDIT:
If you are running on a Web Server using ASP.NET or in general IIS the new process executes on the Web server with restricted permissions. I point you out this answer that could explain the cause of your problem.
However the code you are using doesn't print any error message. You probably don't have access to the directory where the AcroRd32.exe is located.
Let's take this function from the article you posted:
public static Boolean PrintPDFs(string pdfFileName)
{
try
{
Process proc = new Process();
proc.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
proc.StartInfo.Verb = "print";
//Define location of adobe reader/command line
//switches to launch adobe in "print" mode
proc.StartInfo.FileName =
@"C:\Program Files (x86)\Adobe\Reader 11.0\Reader\AcroRd32.exe";
proc.StartInfo.Arguments = String.Format(@"/p /h {0}", pdfFileName);
proc.StartInfo.UseShellExecute = false;
proc.StartInfo.CreateNoWindow = true;
proc.Start();
proc.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
if (proc.HasExited == false)
{
proc.WaitForExit(10000);
}
proc.EnableRaisingEvents = true;
proc.Close();
KillAdobe("AcroRd32");
return true;
}
catch
{
return false;
}
}
PrintPDFs uses a process, which is called by the .NET framework using the Process class. In the StartInfo option you look carefully two options are set:
proc.StartInfo.UseShellExecute = false;
proc.StartInfo.CreateNoWindow = true;
proc.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
The first redirect the standard output stream to your application while the second hides the cmd window. The former is handy to use process without showing to the user a command window but the latter hide the console window. The main drawback is, if you're debugging, that you probably won't see error coming through.
One way to debug it would require to add the following to lines:
proc.StartInfo.RedirectStandardOutput = true;
proc.Start();
Console.WriteLine(proc.StandardOutput.ReadToEnd());
Another property you can look at is ExitCode. If that is greather than zero means that your process exit with some error.
hope it helps.