Dark brotherhood "Bound until death" doesn't work. Help?

[Suzuki Joe]

The dark brotherhood quest "Bound until death" is in the first few main missions [not counting the redguard side quest giver] that Astrid gives you. It's a bit after Cicero tries to talk to the Night Mother.

The problem I have is this; The quest journal. When I first saw it, I thought that it only briefed you on missions in case you forgot how or what to do in them. Apparently it serves a greater purpose; you can't do any quests without it. When Astrid told me about the wedding and briefed me the details, there was no objective marker. So I thought "Maybe when I get to Solitude, one will show up." Nope. So I checked my quest log, and it wasn't there.
I read up on some forums, and people said that imperial sympathizers were having this problem, i.e. the people who chose the Imperial legion's questline, like I did. This is just a hypothesis at the moment, because OP didn't say anything about how that ties into cockblocking the mission. I fear I can't continue in the dark brotherhood questline without doing this mission. How do I get past this? How can I start the mission? I've composed a list of things I did. I really hate to use the console because that's where cheats are executed, but I knew I was using it for a different purpose. I still feel like I cheated, because I used the console at all.

Things I've tried:

Restarting Skyrim
Restarting Steam
Using console commands to force complete the mission
Killing the bride in her home [Doesn't work, she's an essential]
Restarting my computer
Clearing up other quests and restarting [To make room for the new one]
Bashing my head against the wall
Spending 7 hours straight on forums, to no avail

Please help.

[Suzuki Joe]

Try verifying the game cache, if you haven't already.

[StormWing]

I know this is an old post but for anyone that is still having this issue, I did "completequest DB05" (minus ") then
"startquest DB06" (minus ") and it fixed the issue as far as I know. I literally just fixed the issue, Save Before you do this! as it may cause issues later on down the road.