I have the Promises to Keep quest that you pick up in Riften from Louis Letrush. I talked to Sibbi and my journal read to acquire Frost's Lineage Papers. Well, as I'm wandering around town I run into Maven. I speak with her and I see an option to tell her about the theft I was asked to perform. Afterwards the quest updates that I apparently had the papers but wouldn't give me the next step and I didn't have the papers in my inventory. Louis is nowhere to be found and Sibbi isn't much help either. Anyone else have this issue or know what I'm supposed to do?

I'm having the same issue.
I decided to just travel to the lodge and steal Frost but now I don't know where to deliver him.

I figured it out. Even though the quest log says you have the papers you still need to go to the lodge and steal the papers. Then once you steal Frost an icon will appear showing you were to meet with Louis Letrush

Thanks. I'll go back to the lodge to steal the papers.

Thanks for the answer to this, but still having a problem with this. I have gone from top to bottom of the lodge, and cant find the papers anywhere. Got the optional stash but nothing else.

Any clues as to where they are in the lodge would be very welcome. Have done two bedrooms with some nice loot, and all 3 floors, and pickpocketed every guard but no sign of these papers. And I have stolen the horse, but quest hasnt updated.

Cheers,

Sirac

The papers in the basemant, sitting on a box/chest. They are around the corner from the loot stash optional marker if you have that. They are just a small yellowish folded paper. Not really obvious, but not inside a box or chest or anything.