Add Listing button takes user to file not found

The Add Listing button takes me to a file not found when using directory short codes.

http://cronulla.tradr.com.au/listings-shortcodes/

Click the 'Add Listing' button takes me here:

http://cronulla.tradr.com.au/listings/add-listing/

Which is file not found.

Any ideas?

Cheers,

Johnny