Can't get the Dark Brotherhood quest "Bound until Death" to start

I finished the quest before it and Astrid gave me the details of 'Bound until Death': to head out to kill a woman on her wedding day. However, the quest log never updates. I went to Solitude and there was no wedding going on.

Here's what I've tried to do to fix it:

• Loaded an older save to try again.

• Using the console for setstate DB05 10, startquest DB05 <- nothing happened.

• Using the console for completequest DB05 <- worked, but then I didn't get the following quest nor the reward for the quest.

• Doing all the regular assassination missions first.

• Creating a mod to make DB05 start as loaded. I may have done it wrong as I've never modded a quest before.

• Turned off the unofficial patch mod.

• Smacking Astrid with a mace and paying the fine.

• Attempted to kill the entire Dark Brotherhood, but they kept getting back up. Cheaters.

The only other possible reason for the quest going bad that I've seen, is when you're in a certain part of one of the Civil War quests for either faction, but I haven't joined either of them.

Any ideas? I'm feeling pretty stuck here.

Had this same problem. The only thing to do is go into the console and use: setstage db06 05. This will start the next quest 'Breaching Security'.

This should put you in the next set of quests for the Dark Brotherhood.