I have recently bought both the citadel and omega dlcs for xbox 360, I am now unable to launch either of them. I have played through to priority: thessia and still received no in-game emails about either of these. Any help given would be greatly appreciated.
When Can I Play the Citadel DLC?
You can play the Citadel DLC any time after stopping the Cerberus coup attempt on the Citadel and before beginning your attack on Cronos Station.
How do I access the Omega content?
The Omega missions are available anytime after Shepard has completed the main game mission Priority: Palaven and has already spoken to Aria in Purgatory on the Citadel. Once Shepard returns to the Normandy and checks his/her email, there will be a message from Aria explaining what to do next. All Omega missions take place before the attack on Cronos Station.
From EA FAQ/Help
