If you get the error below when trying to start navigation, there's no navigable map data yet for the country where you try to navigate and you can't use navigation in this area.
“Sorry, can't find your route. Navigation is not yet available in your country."
As Nokia has updated the service offering for Nokia Drive navigation on it’s range of WP8 Lumia devices, we also want to ensure that the quality of navigation and map data is the best for Lumia WP8 users. As such, we have changed some of the countries that are supported to ensure that only the best level of service is available.