Ubuntu :: Applications / System Menus Are Empty

In trying to fix issues I have been having with my display, I seem to have inadvertently removed all applications from my menu, which is rather annoying. I'm not sure how. I've attached a couple of screenshots to display this.

When trying to access the 'Main Menu' option from the Gnome Control Center, I get the following error in the command line:

Code:
Traceback (most recent call last):
File "/usr/bin/alacarte", line 36, in <module>
main()
File "/usr/bin/alacarte", line 32, in main
app = MainWindow(datadir, version, sys.argv)

[Code].....