En Masse Entertainment has gifted all players with an extra seven days of free game time due to glitches getting players into the game following the F2P announcement last week. According to the post, all "past, present and future" players will receive the boon.
We’ve seen a great response to TERA: Rising, our transition to making TERA free for everyone. In addition to that great news, we also reactivated all past subscribers for seven days, giving you a chance to come back and experience TERA again.
Unfortunately, we’ve had a few technical difficulties during this reactivation period. These made it difficult for some players to get into game. The good news is that those issues have now been addressed and everyone can once again access TERA.
Read the full post on the TERA site.