I have a little problem with all NPC´s above prison in fortress in Fort Joy. Guards and even padadin don´t respond any actions. I am not able to talk with anyone in fortress. I can attack them but they don´t care though.

did you teleport your way in?

I did. But not to fortress at all. I teleported 1 character under the waterfall near dead elf for loot his hand. Then I´ve noticed a cave which I can interact .So I walked in and all my characters appeared in prison. In cell with inprisoned dwarf, precisely. I killed Houndmaster and got key from doors. When I walked in countryard where Paladin is all characters ignores me. Even I attack them.

This happened to me too until I actually escaped the prison. After that the quest updated and the guards turned into attack mode. So I guess you have to escaped first and come back if you want to kill them. Or you could of course force attack them using the CTRL key while clicking on a guard.

Had same bug in a co-op game. Was fixed by reloading a save from more than just a few minutes ago (most recent autosave had the problem, but manual save from before coming within activation range of the double doors cleared the problem. Wild speculation: a script failed to load properly.)

I loaded save since arrive on Fort Joy island then fastly try to teleport into the fortress near paladin cork and nothig changed. So far nothing work for me. Meet with tons of topics about exactly this problem, but none of solutions work for me. Seems I got superbuged :(

I had the same issue - I'd come in through the ladder that leads into the court room. That battle worked since it's scripted. But I went down stairs and no one would attack even if I attacked them.

I ended up going outside, and coming to the main gate. The guards outside the fort DID attack me, and once I did that, the guards inside the fort would attack me.