When they changed the invocation system a couple of months ago, one of the new perks of the multiple invokes per day was that one of them would grant you a refinement stone of some kind. What was funny about this was that it was initially randomised which kind of stone you would get, but then you would get the same stone every day, forever.
The result of this was that if you were lucky and got a useful stone the first time, you would continue to get something useful every day. This was true for my cleric and my rogue for example. If you were unlucky, you might end up like my great weapon fighter, who has a pile of over fifty stability stones (bound to character of course) and no stability artifact to use them on. This system seemed rather odd and like it was probably bugged.
This seems to have been confirmed with the latest patch, since they "fixed" it now so that invoking grants a goodie bag instead, which will then contain a random stone. This is good news for my great weapon fighter, but bad news for my other characters, who now suddenly have a chance of getting something useless. Worse, since you can now get something different out of a whole selection of useless items, it's going to hurt your inventory space, and much worse than those 50+ stability stones ever did.
Also, never one to leave out an opportunity to monetise, Cryptic seems to have programmed the system in such a way that you also get a coupon for the Zen store from every single one of those goodie bags, which I find quite annoying. I don't mind finding them out in the world on occasion, but having multiples of them dumped in my inventory every day seems kind of... pushy.
I know it won't happen, but I kind of want that bug back.