The guild and guilds tutorial quest still will not update after talking to Aven. Want to finish the achievement but can't. Test server. Am I doing something wrong?
No, I don't think you're doing something wrong. I tried this yesterday, with the same results you had. There was a post in the bugs thread about it as well. Seemed to break right around the time a lot of people were being unguilded, but I don't know for sure if one thing has to do with another.
I've done this quest with three out of my four characters. You do NOT have to be in a guild to do the quest: if you're not already in a guild when you start the quest, you'll be offered a chance to join a guild as part of the quest so you can visit the guild hall and complete the tutorial. Note: after you join the guild, stay in it at least until you've gone all the way through the guild hall tutorial quests. My first character quit the guild too soon, and had to jump through some hoops to rejoin so he could finish the quest. My fourth character couldn't do the quest because something broke it recently, as reported in the bug thread a few days ago. (The quest dies before you even get to the point where you need to be in a guild.)
This is now fixed internally. A recent modification to guild IDs changed the value returned when retrieving the guild ID of a character that was not in a guild. The scripts on these dialogues were checking for -1 when they should now be checking for 0. We will look into a hotfix for this in the near future. Thanks for letting us know!