What is wrong with the server?

It's been happening for two days now, I could not log into the game. After I imputed my PIC and the screen would freezes and an error will pop out saying I can't log into the server and brings me back to the main page.

And it also happened once that when I clicked on the game, the game would not appear and an error came out saying the game is down or patching.

What is wrong and what can I do to return into the game?