Once you do three events the Jin barrack will open up to the northern region.
1. The SW kungfu tournament in banshu
2. The music festival in the xiaoyang area
3. Stop mr thistledown at deercave academy after the auqa/tera alliance tournament. In the jiandong area

If I'm right you didn't got to deercave academy. It's north east of linan.

If you've done all the events youll get a cutscene telling you about the jins invading then you go to the barracks in the starting region. And you can start the quest line to open up the region.

Are you doing feather robes or street hero? Feather robes might have you go back to the sire.

Also i haven't done the evil rout for the SW tournament but you might have to talk to the old man you helped on the snow mountain

Not sure if you figured it out yet, but I had the same problem. What fixed it for me (Street Gang route) is going to back to Deercave Academy and talking with Sister Lin and Prodigy of the east, (They are in a building on the east path going to the right and then up.)

Originally posted by kingkeane249:

I cant go to the northen region through the jin barracks. I took the evil route in the southwestern kungfu championship, finished it but its not ticked on the questline.but i heard that the game kust doesnt tick it sometimes. I finished dongting yuelu too and also the taihu lake gang thing along with finding out gu jintang was a traitor. Yet i still cant go the northern region.... why?
Its said that there should be a cutscene after i complete the southwestern chamiponship and dongting yuelu.... but it didnt happen is it a bug?