Good find, Prisoner. It does indeed appear to be a legitimate error. The error occurs within a file named "smblueblood.dlg" and it is actually very easy to fix.
It's not a scripting error... it's simpler than that. It's just a missing line of Brujah dialogue. I think the reason that none of us have ever seen it before is because normally, the player doesn't have very many points in Seduction st such an early stage of the game. Hence the Seduction response never even shows up during our exchange with the blue blood.
Troika apparently used this line...
{ This is a PC response if the player is a brujah }...as a placeholder and then, they totally forgot to write the actual line of dialogue.
Alrighty, I'll have to write the new line myself. Same as I did when I was forced to write Malk-specific dialogue for the initial encounter with Heather.
After I fix it, the new dialogue file will be added to a future TPG hotfix.
Many thanks for your help.
