The most common cause of this is because of not selecting an address from the choices returned by Google Maps when typing your address. This is imperative to do as it ensures the addresss is correctly geo-encoded to a map location.

Another side effect of this is no map will appear on your listing.

To correct this go to the Dashboard and Edit Listing page and start re-typing your address (with or without a street number).

Selecting the correct address as it appears in the choices.