I just helped someone get it this week . We got all the steps and keys done . It sucked waiting each day for the forge to unlock but from start to finish it worked this week . So this bug you speak of ...

[quote]This is an informative post for players who don't yet know about the Izanagi's Burden quest bug For all of the New Light's and uninformed players. Yes the Mysterious Box/Lock and Key quest for Izanagi's Burden is bugged... A quest step isn't spawning and because of this you cannot obtain the Black Armory Key... As far as I'm aware, bungie is working on a fix but for now, you'll just have to go without this particular Exotic... Yes this is somewhat annoying. Yes I am one of the many of you who haven't gotten this sniper. But just be patient... And remember, this isn't a Raid requirement... If players are demanding that you must have Izanagi's, they're wrong... a Whisper of the Worm or D.A.R.C.I. will work just fine. On the other hand, hopefully this is patched very soon. Bungie will most likely get around to it when they aren't working on the Vex Invasion stuff...[/quote] You have to complete quest "rekindle the flames" before she will give you mold.