I just finished the Chosen seal a week ago and wanted to move on to the Warden seal since I never got around to finishing it out last season and they decided to keep it until the end of the year. I only have to complete Harbinger and complete Harbinger with two other guardians equipped with Hawkmoon.
I have Hawkmoon, and last season I started Harbinger and tried to solo it but never ended up finishing. I don't have an icon on my map for the mission, and whenever I go back to the dam where I originally started it, the dam has water running down it, preventing me from scaling the wall to get to where the mission starts. My feathers of light collected for Bird of Prey says 10. I'm on PC.
Is there any way to unlock Harbinger? Only other thing I can think to try is to find someone else who has it on their map and have them take me there, but I'd rather play through it solo before I do the Hawkmoon fireteam triumph.