So I was playing with my friend in co-op and he was hosting the server. After playing through the game I decided to go into single player. I had to redo a few things to get to the outpost, but when I went there my outpost was as if it was from scratch. My progress saved in my missions stating they were completed, however my outpost didn't update. Therefore, I decided to redo the main story missions. Redoing them all did update my outpost, but then came the final story mission. After completing the Glitch Fortress mission again, I could not talk to Esther to activate the Ark in single player. I had activated it in multiplayer to fight the ruin, but it was deactivated in single player. Because of that, it didn't trigger Esther adding the final piece to the Ark. If someone (especially if a dev can acknowledge this) can please get back to me on this that would be great! I would really like to know if there's a solution to this. *EDIT* I found a quick and simple solution that is temporary. I asked my friend who hosted the server to give me his storage folder. From that I deleted my universe folder and pasted his in. My Ark is now activated and my outpost if fully up to date. I hope this helps some people in the mean time!