The missing file likely requires a fresh save, it was erroneously coded and fixed with v.0.20.2 but saves with the error will persist, it isn't necessary to review for anything going forwards so you can just continue and you won't get any bugs.
White Company isn't London, it's not a real website it's a front, you're looking for Fleur/Lydia's maiden name, check the marriage certificate. (If you have the walk-through on the narrator will tell you the answer before you open the PC)