ME2 LE Zaeed and Kasumi DLC not appearing
When I first played ME2 LE (I don't remember exactly when; I think it was about a month after launch), the DLC The Price of Revenge (Zaeed's recruitment and loyalty mission) and Stolen Memory (for Kasumi) worked fine. I recently re-installed ME: LE on a new computer, and just got to ME2; I have completed the Freedom's Progress mission (as well as Dossier: The Professor), but neither has activated. (The messages do not appear at the terminal on the Normandy, and the intro scenes on Omega and the Citadel do not happen.) I have tried launching both through Steam and through Origin; I have also saved and reloaded after moving to a different location, with no effect. The equipment DLC packs still appear, as does the story content for Firewalker and Overlord DLC.
Since I have ME:LE in Steam, clearing the download cache (in Steam > Settings > Downloads) and verifying the integrity of the game cache (there were a number of files that downloaded) fixed the problem -- though I didn't check after the first step, so I can't tell you which one helped or whether both steps were necessary.