I haven't even been able to play single player because I bought a new 360 & a transfer cable. I transferred everything & then I had to shut my internet off & then when I tried to play ME3 it said I was missing a bunch of DLC. But it says all the DLC is on my hard drive. I don't know what the hell happened but it's damn annoying not being able to play my favorite game in the world. So I have to re download them all. I hope I can get everything working again.
I underwent a lot of frustration having my 360 replaced a few months ago, because of the licence issues that are at the root of why that happens.
Because of Microsoft's convoluted licencing system, a whole lot of games on your hard drive are likely to have problems related to DLC, especially if you intend to play them offline.
It sounds like you already know how to address the issue, but for the sake of minimizing further frustration on your part, I'll list everything I know so that you can make sure you've got your bases covered:
- If you have the DLC on the hard drive and are logged in online, you should theoretically be able to play with the DLC functioning. If you attempt to play offline, that's usually where the problems will be.
- A critical step is to perform a "Licence Transfer." This is done while logged in online, and it is found under your account options. You can do that up to three times (I can't remember if it is three times per year, or three times per quarter, but it's something like that.)
- The licence transfer should make everything work while logged in online, but it will not update the licences for DLC that was downloaded on a different console. That means that the DLC still won't work when you are offline.
- Re-downloading the DLC updates the licence to the current console if that console is the one to which you transferred your licence. Once you have re-downloaded all the DLC, most games will now work online and offline normally - but not all of them.
- Any game that was principally or in part downloaded (ie not installed from a disc that is in the drive when you play) can still fail to work with its DLC. In most cases, re-downloading and re-installing it will resolve the remaining licence issues.
- After all that, any games that are still not working may require help from Microsoft tech support.