I beat all of Celestia back when 60 was a characters max level, then wound up leaving the game for sometime. I started back a few months ago and for some reason I cannot progress to Zafaria. When I level Merle and my school teacher (my school is death) tell me to come see them and neither of them have anything for me. So am I glitched or am I missing something? But as I said, I looked up all the progressing quests and I'm sure I've done them all because the NPC's that assign them have nothing above their heads as well.
My first suggestion is to contact support and let them check into it. (Do this first) It may just be something simple that KI can fix quickly.
My second suggestion is that if you have been away from the game for any length of time, you may want to try to reload it. You may not have received all the update patches needed to progress.
