Can't open the chest.
There is a thread about this problem over in “Game Bugs”. Devs are already investigating.
Same problem with me , cant get any interactions from him, i talked to him and got eh achhievement, but no item. The it says if bag full (mine was almost empty ) to click chest , am unable to click it or get any interaction from it , then talk to tixx again he says only one gift allowed.
I tried relogging , rezoning , changing characters , get nothing from tixx now he wont acknowledge he gave me nothing.
So think he should be renamed TRixx !!
have send bug reports and posted on here hope devs/anet can get this sorted shortly for us having this issue