I recently downloaded Dawnguard using my brother profile as he had enough points. I tried playing it on my profile and it would not let me run the DLC. I keep getting this message when I tried to play, "save file cannot be accessed because content this saves rely's on does not exist." I am unable to play any of my saves now nor are the other people who use my xbox and play Skyrim. I have tried reinstalling and and removing it to no avail nor starting a new game.

Hoping someone can help with this as it essentially renders my game useless.

You cannot use it on your profile since it is your brothers profile that have the ownership of it. Microsoft, and any other company that sell something really, don't like that one person can buy it and many people use it so they restrict the usage of online bought content to the profile with the ownership rights.

If it's on the same xbox you should be able to use it. I can use anything downloaded on any of my other profiles. "save file cannot be accessed because content this saves rely's on does not exist." Usually means that something happened with the patch. Try turning on your brothers profile, starting up the game and seeing if it tries downloading the patch. Could be that you accidently deleted patch content or something and so your save profile is trying to load up a game that rely's on the content from the patched version and therefore cannot load.

Uh...no, you can't do that with anything you download on the 360.

It's attached to the profile that downloaded it. Are you saying you can't play any of your saves even after removing DG completely?