That window appears whenever an
Applescript is loaded, and the System can't find an App which the script tells to do something:
Tell blocks.
One of your Automator or Keyboard maestro scripts is trying to use "GrowlHelperApp"
If you don't have:
~/Library/PreferencePanes/Growl.prefPane/Contents/Resources/GrowlHelperApp.app
either install it and select it in the dialog window, or find and eliminate the Applescript that is calling it.