Okay, so awhile back (like 3 months ago) i was playing skyrim. And i was walking right onto dragon's bridge doing a quest for the DB (At least i believe i was from my memory) and well randomly a quest failure came up saying that I failed this certain quest i never started....any ideas?

What quest failed?

I've never heard of this happening in the game, it usually doesn't tell you when something fails without having the quest first.

(Use to be) If you kill the Orcs at a certain stronghold, you get Malacath's Daedric Quest Failed and you don't need to start it. So it is possible but what quest could it be in Dragon Bridge?

You can get quest failure messages in game. Only quest I know of conjoining Dragon Bridge and Dark Brotherhood is if you kill Astrid - then you talk to a guard anywhere, and he sends you to Dragon Bridge to talk to Penitus Oculatus Commander Maro....

Not sure why you'd get a quest failure message for that though.

Are you doing any of the MQ? I seem to remember reading something on the forum.. I don't know, one of the more regulars may be able to answer this better though. It was something to do with the peace meeting..? Not sure, just a stab.

Why dont you just check your quest log? a failed quest should show up in the completed list.

Are you referring to the quest "The Horn of Jorgen Stormblower" (sp)?

It means the quest giver or person involved in the quest has died. Maybe a dragon attack or something.
I was delivering some Quicksilver Ore from Shor's Stone to Riften, and after I got it from the blacksmith there, a dragon attacked and he died. Somehow I still failed the quest and there was no longer the option to talk to the alchemist in Riften about passing her the Quicksilver Ore.

Are you talking about Destroy the Dark Brotherhood or kill Maro's son on a security tour?