title: gtkmm & glade - multiple window not working
body: <p>using gtkmm.h header file, I created a simple app with glade template. Signal works fine but I am trying to change window or open another window on click event signal. member function fires but another window is not opening. If i create different Gtk::Application::create() then also 2nd window open after closing 1st one. Does anyone have any idea about this.?
  Anything can be helpful.</p>
  
  <p><code>GLib-GIO-CRITICAL **: 19:45:21.107: g_application_parse_command_line: assertion '!application-&gt;priv-&gt;options_parsed' failed</code></p>
  
  <p>and this is the error that shows in terminal.</p>
  
  <p>event after creating different instances for Application and Builder below error shows up and 2nd window still fails.</p>
  
  <p><code>Failed to register: An object is already exported for the interface org.gtk.Application at /org/gtk/Application/anonymous</code></p>