Welcome to the site. This section of the forum is actually for site support - i.e. issues related to the website. If you can tell us the year of your car I can move your post to the correct section, where more people familiar with the model will see your post.
On the subject, I would suspect there might be an issue with the media containing the maps for your sat-nav (usually a DVD or SD card); I might be wrong, but I think if the media isn't present, the message is more explicit about that, so the message you're getting might indicate that the media is somehow unreadable. Again, if you can tell us the year of the car (and ideally the type of infotainment system), people in the model specific section might have better advice.