Game client needs update (Error 1012)

Anyone else getting this?

Getting error 1012 (Game version needs update) after hitting the "START" button on the main screen.
Boots me out of the game & launcher, but upon reopening the launcher, it doesn't force any kind of update like it normally would if I did have an out of date version.

I was playing earlier today, then logged off to go to Uni. After I came home I tried logging in and this happened. Computer was completely unattended the whole time so I can't imagine I did something between logging off and attempting to login tonight.

Never mind. A reboot seemed to fix it.

Unsolved mystery.