The check file button is grayed out upon the update of the game files, therefore resulting in the launcher is up to date notice and the closing of the application when you click the OK button on that notice...
I am having the same problem. I wasnt sure if anyone else had this problem so i posted it up on the tech issues part of the forum. But it seems to do this to me as well after every maintenece.. I suggest to sit and wait it out.
Last time this happened only certain people could access the game and other couldnt. I am assuming to just wait because even I went through the manual patch and even re-downloaded and installed the game again just recently. same message box occurs.