What is the problem?

private void highToolStripMenuItem_Click(object sender, EventArgs e)
        {
            foreach (Process process in processeslist)
            {
                try
                {
                    if (process.ProcessName == listview.SelectedItems[0].Text)
                    {
                        process.PriorityClass = ProcessPriorityClass.High;
                    }
                }

                catch (Exception ex)
                {
                    MessageBox.Show("SystemProcess priority cannot be changed");
                    break;
                }

                else
                {
                    process.PriorityClass = ProcessPriorityClass.High;
                }
            }
        }