Bugged Gate or What?

My friend and I were doing a quest the other night that's supposed to bring us to a town. We were doing fine with the henchies. Before we can finish the quest, my friend has to logout because of an emergency. So, I decided to continue the quest without my friend.

Finally, after earning 60% DP, I was able to reach the end of the quest. after completing everything I ended up talking to a guard and told me something about entering the town. But I cannot enter the gate because it is closed. I couldn't do anything about it so i decided to go back to Marketplace and I realized that I have to redo the 2 hours work.

Is this a bug or what?

what quest and town was this?

I just arrived in the Market place. I was told to find a man, then the man told me to find the mother of a certain person who died. then the mother told me to find someone, etc. etc.

My friend and I were doing the quest together. He left before the end of the quest.