It looks like the Gabon registry is having issues of some kind. While it’s not unheard of for a domain registry operator to have technical difficulties they’re usually “blips”.
In the case of the .ga registry, however, it looks like the zone has been having serious issues since September of last year!
Stéphane Bortzmeyer conducted a detailed analysis (in French) of what could be seen from the outside.
Short version – it ain’t working.
Basically the .ga namespace is offline. It might be a simple matter of a firewall, router, loadbalancer or other device not passing packets of data back and forth from the domain registry’s DNS servers, or it could be something more complicated. In either case it looks like .ga domain names currently are not resolving, so the Gabon registry is offline.
I don’t think the entire .ga namespace has been shut down as some .ga websites are very much accessible https://www.google.com/search?q=site%3A.ga&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a