Ubuntu can't open Terminal Application

$ gnome-terminal 
# Error constructing proxy for org.gnome.Terminal:/org/gnome/Terminal/Factory0: 
  Error calling StartServiceByName for org.gnome.Terminal: Timeout was reached

Problem with "gnome-terminal" on Gnome 3.12.2 - Ask Ubuntu

If you are using Code::Blocks to develop a GUI application and you are unable to open the GUI app, you can try the following steps。

Try to regenerate locales first:
# locale-gen

And then:
# localectl set-locale LANG=“en_US.UTF-8”

And reboot.