Cant Complete "Brewmaster" Achevment
You can buy it on the Trading Post for a few copper.
I had this issue where everytime I went there to try to get it, it was never available. I finally got it on Tuesday right after the patch. If it is again not working the best I can suggest is to go there right after the next Tuesday patch on the 10th, or if they do another fix, go right there.
Same thing with the Ancient Stone Summit Shoulder Spike for treasure hunter collection. The event never restart.