When I interviewed Perfect World Entertainment back in 2013, we were assured that despite servers shutting down in Europe and Korea, that business would continue as usual. That business, I assume was solely predicated on the continuing survival of MAIET Entertainment, the game’s developer. Well MAIET Entertainment as a company is dead and buried, and unfortunately that has lead to issues cropping up in the game that cannot be fixed.
As a result, Perfect World Entertainment has announced that the servers will go dark next month.
We have significant news to share regarding RaiderZ. Over the past weeks, RaiderZ has seen a few different instances where the game has had issues with the server. In the past, we have been working with MAIET, the developer of RaiderZ, in order to troubleshoot and solve issues to keep the game available for the players. Unfortunately, MAIET is no longer operating anymore.
Back in 2013, PWE expressed interest to me in a license similar to that of Neowiz in Japan, who were creating their own content. Whether that would have permitted the publisher to keep going should MAIET go out of business is unknown, especially since the Japanese server shut down earlier this year in March.
From my interview:
That’s a great question, but it’s not something that we’ve considered at this point. We’ve heard great things out of Japan, and are always open to new opportunities in order to ensure the continued success of the game, and making a positive experience for the players.
(Source: Perfect World Entertainment)
MMO Fallout 
I think GunZ 2 (from the same developer) is not faring well unlike the first installment.