Seen this come up too many times on the help forums so I believe its something that should be pinned since people don't like to read in game. Xur's weapon and armor upgrades were for pre dlc vets to upgrade said exotic armors/weapons to match Crotas End content. Meaning your fav 300 maxed exotic weapon could now be upgraded so that you can regrind it to 331. Same for exotic armor. As soon as you upgrade your weapon it already does more damage as it starts off at 302 damage. You would need to re-level it but it would be alot faster than the first time you did it. If you came in at or after Christmas you most likely won't have to deal with upgrades since all exotic drops and bounties have been set to drop at 302. The only things you might consider upgrading is exotic armor if xur sells one that has better strength/intelligence/discipline than your current one (people have called this re rolling). Some of you christmas guardians are pissed for two reasons: 1. You by mistake tried to upgrade an already 331 weapon only to have it reset to 302 (you should of just used the compare feature and see that it wasn't going to be upgraded above 331) 2. You were silly and thought that upgrading your 300 maxed weapon was going to auto max it to 331 (you're new here so you didn't know that bungie likes to have us grind for weapons and gear) Now the first one could be solved by having it set that 331 weapons shouldn't be highlighted for upgrade but honestly there are more important bugs and glitches that bungie should get to first. This current "bug" just requires reading.