After the quest "Hard Times", Karliah told me to meet her at the Ragged Flagon, but it never came up in my journal or even came up as a quest.
I go to meet her at the Ragged Flagon and she isn't there. Tried going back to the Sanctum where we first met and she was there, trapped behind a door. I opened the door to free her and tried talking again but she doesn't say anything. I tried going back to the Ragged Flagon again but she still is not there.