Help! Breaching Security mission.

[evil larry]

During the "Breaching Security" mission that you are given from Gabriella in the Dark Brotherhood, i cannot get the Incriminating letter. It makes no sense, i have all DLC and disabled all DLC then tred, but it still does no work. I have spoken to Gabriella multiple times and it always says that the Ïncriminating letter" was added to my inventory, but it is no where to be found, not in weapons, book, keys or misc. But when i open "player.showinventory" in console it says i have it, please help. I bought the DLC mid way into playing the campagin.