Trouble Starting Tribunal Questline

Apparently in order to start the tribunal questline, you have to fall asleep and then a DB assassin will attack you. I'm level 6 now and have tried this at other levels and it still hasn't worked, could anybody help me with this?

From the FAQ:

» How do I start the Tribunal and Bloodmoon quests?
For Tribunal, you have to complete either the Morrowind main quest OR one of the major faction questlines and be level 15 or above. This is an intentional change from original Morrowind (where Tribunal questline could be started at level 1, right after new game) as Tribunal expansion was made for high level characters and this makes more sense story-wise.

Trouble Starting Tribunal Questline

From the FAQ:

Ah, thank you.