My progress in the game is as follows: Lowland meadows and Marin forest are both completed. I have received the short cutscene of the crow/raven giving my character a letter from Roan. I then journeyed to the Cerim gate. I did NOT speak to Roan or the Watcher (I believe this may be the cause of the bug). Once I arrived at the gate, basically everything is missing INCLUDING THE GATE.
Provided video:
