We'll be doing some planned maintenance to our game server network during off-peak. As a precaution, we'll be disabling Ranked from 0400am - 0600am AEDT (Sydney time) on the 15th Oct 2015. This is just a precaution, as we don't want to risk any precious LP! Normal queues will remain active during this time.
If you've got any questions, let me know.