I mentioned it on another post where people were mentioning an error in this quest in the general discussions and thought having a post about it and what I have found on it so far.

The quest is believe the name was sinister revelations it is when Ludo has you go into memories with Janus. There is two bugs that I have found when playing the 1st one comes in the dialogue options in this sequence and the other happens based on what choices you make. The 1st issue comes up when select the Claire option instead of solitude as you progress the dialogue it suddenly goes to the menu artwork and takes away all the dialogue and cant do anything except load or save and things like that. The other part comes with what dialogue options you choose when talking with Lucy. The time I encountered it was when I was not flirty with Lucy and was selecting options that didn't reveal much and had me only make 2 options to pay her and with this you get all the info would need about claire and stuff but after this the quest would say speak to the barkeep again. I loaded back and did this part again this time was flirty I don't think this matters and then I chose options that was less covert and ended up in mid conversation giving me Claires trail quest which did not pop up before and was able to have 3 times where paid her. I assume the issue was the trigger for the quest activating or progressing. If didn't have this specific dialogue choices the quest would never be given and would be stuck with sinister revelations speak to barkeep.