[Wanderer] Can't do 2nd job advancement

So I got to level 50 and used the teleport item to go to the desert place, but I assumed that the quest that popped up on the lower right corner of the screen was to do the advancement so I warped out of the desert place to do the quest, but apparently it was just some random quest and not for job advancement and now I can't get back into the desert area. It won't let me into the portal even though I'm the appropriate level. Any idea how to fix this problem?