Currently Unavailable, means that particular content (movie, series, show) is not available in your region/country. The content can still be bought from amazon, but is not available for streaming through prime subscription. Hope this helped.
Check your Internet connection. You may need to restart your connected device and/or router. If you're able to connect to the Internet on other devices, update your connect device's DNS settings. Please check with your device's manufacturer for further details.