On this quest I am stuck on the task "Reach Buckingham Longhouse", when I get there there is the prompt to "Force Open" the door, however the AI for both Basim and Sigurd is bugged and they just stand around. From my testing I have founf the following:
Whistling causes Basim and Sigurd to walk to you
Being on a horse causes them to follow you
They will fight any enemies that come over, but then will return to their glitched state

Now onto things that I have done in an attempt to fix this:
Travelling back and away
Meditating
Using the Horn
Quitting and reloading
Exiting the game and reloading
Dying and Reloading
Forcing them to move close to the door

None of the above seemed to have any affect, and my most recent save is around 20 hours in the past, and as such I am not going to go back that far. I have seen that this is a prevalent issue, however it has not shown up on the Known Issues list because it is not "repeatable". To this end I am going to stipulate exactly how this occurred:

1. Arrived at Buckingham
2. Walked to the alehouse by crossing the river
3. Lost 1 round of Orlog, then won the next
4. Talked to the alewife
5. Used charisma to get her to tell me where Sigurd was
6. Crossed the river to get to the fish house
7. Had the cutscene with Sigurd and Basim play
8. Crossed the river again and made my way to the longhouse
9. Remained in stealth until I got to the side door of the longhouse
10. Killed all nearby enemies

After this sequence of events the quest became stuck. I hope that this can be resolved, or at the very least be placed onto the known issues list to be resolved soon.

On this quest I am stuck on the task "Reach Buckingham Longhouse", when I get there there is the prompt to "Force Open" the door, however the AI for both Basim and Sigurd is bugged and they just stand around. From my testing I have founf the following:
Whistling causes Basim and Sigurd to walk to you
Being on a horse causes them to follow you
They will fight any enemies that come over, but then will return to their glitched state

Now onto things that I have done in an attempt to fix this:
Travelling back and away
Meditating
Using the Horn
Quitting and reloading
Exiting the game and reloading
Dying and Reloading
Forcing them to move close to the door

None of the above seemed to have any affect, and my most recent save is around 20 hours in the past, and as such I am not going to go back that far. I have seen that this is a prevalent issue, however it has not shown up on the Known Issues list because it is not "repeatable". To this end I am going to stipulate exactly how this occurred:

1. Arrived at Buckingham
2. Walked to the alehouse by crossing the river
3. Lost 1 round of Orlog, then won the next
4. Talked to the alewife
5. Used charisma to get her to tell me where Sigurd was
6. Crossed the river to get to the fish house
7. Had the cutscene with Sigurd and Basim play
8. Crossed the river again and made my way to the longhouse
9. Remained in stealth until I got to the side door of the longhouse
10. Killed all nearby enemies

After this sequence of events the quest became stuck. I hope that this can be resolved, or at the very least be placed onto the known issues list to be resolved soon.