Premium Crate Key bought off the listings not working.

http://imgur.com/a/DX5E9

I bought the key 7PM EST+3 from listings and it refused to work.
Lister of the item was @PanzerShrimp , yesterday i bought 4 keys of the same serial in listings but they worked just fine.

 

I will issue you a refund for 4295.36 shortly.

 

Also this tends to happen on the last key purchased in the market.

 

What's odd to me is that 1) There were 4 keys of the same serial, and 2) they all worked.

Is this working as intended? @irritatingness @Deathbyrussian

 

I believe the serial is just to link the set of keys with a purchase on the site. I think the server looks up info on the serial number, sees how many uses are available, then deducts one each time the key is used. @HelixSpiral

 

D'oh. That makes sense. Whoops.

 

Did you attempt opening a key at the same time as him with the same serial? That was how this was happening previously but I added a check to ensure any serial can only be opened one at a time to prevent this.

 

No, I used about 4-6 of them when i first bought the set, then put the rest onto the market.