I have a file I've put about 50 hours into, and earlier I went to play again and was greeted by a message saying I require some missing DLC to play that file.
Trouble is, I've only downloaded the code that came with the brand new copy of the game. I looked into my box's memory and it shows that the House of Valor DLC is installed, is there a second part I deleted somehow? If I need to provide more info to get help I can.
Did you run maintenance on your hard drive? That deletes patches and you may be currently unable to load your DLC-enabled save. Try loading the game while online and you'll get a prompt to download an update.
Or maybe your save somehow got corrupted. It can't be fixed if that's the case and you'll need to load an earlier one.
Friend of mine resolved this by deleting ALL dlc then downloading it all again. This includes House of Valor, the Gamestop / Amazon dlc weapons/items, and the ME3 weapons. I hope it works for you too. --- Unofficial Underground Car Tuning/Street Racing Board http://boards.gamefaqs.com/gfaqs/gentopic.php?board=585168