I was able to play for a few hours and logged off. Tried logging in the other day to get an error saying I didn't have a valid license (I do) or I didn't have a subscription (why would I pay for one during a free to play event?)

I don't understand why I was able to play a few days ago, but I can't now. The game is free to play until the 30th. Why can't I log on anymore?