When I attempt to launch the game, after logging in, the client window goes black with the message:

Connection Failed: You do not have the current version of the client installed.

I then must press a Quit button, which closes the client. I am not a computer person and have no idea why this would suddenly start happening. Is there something I can do, hopefully quickly?

My characters need to visit the Spring Festival every single day or I will fail to complete the wrapper quests after investing hundreds of hours of my time. I really need this fixed or I will lose an immense amount of effort.