var thread = new Thread(() => ThreadOpenFile(args));
thread.TrySetApartmentState(ApartmentState.STA);
thread.Start();

private static void ThreadOpenFile(string[] args)
{
  ApplicationContext appCnxt= new ApplicationContext(new newForm(args[1]));
  Application.Run(appCnxt);
}

private static void ThreadOpenFile(string[] args)
{
  Application.Run(new newForm(args[1]));
}