I asked few days ago about how to get a list of countries in Swift, and you solved the first part of it (here: [Swift - Get list of countries](https://stackoverflow.com/questions/24315741/swift-get-list-of-countries)), but I am not able to get the final countries list because it gives an error:

```
var countries: NSMutableArray = NSMutableArray()
countries = NSMutableArray(capacity: (NSLocale.ISOCountryCodes().count))
for countryCode : AnyObject in NSLocale.ISOCountryCodes() {
  let dictionary : NSDictionary = NSDictionary(object:countryCode, forKey:NSLocaleCountryCode)
  let identifier : NSString     = NSLocale.localeIdentifierFromComponents(dictionary)
  // next line - fatal error: Can't unwrap Optional.None
  let country    : NSString     = 
    NSLocale.currentLocale().displayNameForKey(NSLocaleIdentifier, value: identifier)
  countries.addObject(country)
}
println(countries)

```

What does the "fatal error: Can't unwrap Optional.None" error mean? I've been trying and searching about it but I haven't find the solution yet :/

Million thanks :)