To use this extension, you need to enable extensions first. Otherwise you get the error below.
To enable extensions, proceed as follows:
Advanced tab, enable Show Develop menu in menu barDevelop menu and select Enable ExtensionsAdBlock.safariextz)
Discussion
Can't find the “Enable Extensions” menu item under “Develop.”
(For other people with trouble finding the “Develop” menu bar, press Alt to show the menu bar.)
This one is a go!
Thanks! you are the king of kings.