I am having trouble starting the content for Forgotten Sanctum DLC.

I have:

checked it is listed on the main menu page as installed

completed Magran's Teeth and Mapping the Archipelago: Tikawara.

Made my way to the centre of the Halls Unseen - cannot find any stairs.

I am at the point where I am able to go to Ukaizo (have the coming storm quest left), but not sure I have allied with a faction - I was going for Huana and I dont have any of their quests left.

 

So to start Forgotten Sanctum DLC what specifically do I now need to do?

•    If you have done so, you will encounter an earthquake event that will allow the DLC to be accessed.

•    Sail to the Hall of the Unseen located on an uncharted island directly south of Tikawara.

•    Venture inside the Halls of the Unseen, make your way to the center, and go down the stairs to start the DLC.

The above steps are when it is possible - but not recommended - to start the DLC. Instead, to ensure you are around the appropriate power level, there is an additional event that can fire:

•    Make sure the earthquake has occurred due to completing either Magran's Teeth or Mapping the Archipelago: Tikawara.

•    You must be ready to journey to the end of the game to Ukaizo. This is either by decking your ship out with the blackwood hull and dragonwing sails, or by allying with one of the four major factions.

•    Sail on the world map for 12-24 hours in game time. This will trigger an encounter where Llengrath lands on your ship to speak to you. This will start the first quest of the Forgotten Sanctum DLC.

•    Sail to the Hall of the Unseen located on an uncharted island directly south of Tikawara.

•    Venture inside the Halls of the Unseen, make your way to the center, and go down the stairs to start the DLC.

It sounds like the earthquake scripted interaction that pre-empts the DLC might not have triggered yet?

You can check of the variables associated with it by opening the console( tilde ~ or backtick ` key located next to the 1 opens the console).

Then enter the following commands:

PrintGlobal LAX3_b_earthquake_occurred &
PrintGlobal LAX3_b_earthquake_wave_encounter_occurred

If the combat log displays: 

'LAX3_b_earthquake_occurred': 1
'LAX3_b_earthquake_wave_encounter_occurred': 0

Then the scripted interaction should in theory be triggering fairly soon. I forget if there is an exact place for it to trigger, but I want to say heading into Nekataka and then resting at the inn and then leaving the city by sea and sailing some ways out to sea should work to trigger it?