Mass Effect 2 won't connect to cerberus network. DLC does not appear

I will provide you several workarounds, please accept as a solution if one of following steps helped you to solve this issue. If not, please respond that we can look for other possible solutions.

To make sure that no corrupt data causing your issue, you should clear your cache:

1. From the dashboard, click on My Xbox.
2. Select System Settings.
3. Select Storage.
4. Highlight Hard Drive Device.
5. Press Y to select Device Options, then Clear System Cache.
6. Reboot your console.

Redownload the updates for the game. NOTE: Not all games have a Title Update File.

1. From the Dashboard, click on My Xbox.
2. Select System Settings.
3. Select Storage.
4. Select Hard Drive Device by pressing A.
5. Select Games and Apps.
6. Select Game Title.
7. Delete Title Update File.
8. Restart Game.
9. Download the update when prompted.

Cheers                                                                                                                                                                       
Basti