Found a hacky way if luna is the only clue holding you back:
When the error happens, go to "Console", paste the following 4 lines into the console, press the enter key, press the escape key, then "Ignore".
quest13.clues["luna_talk"] = True
quest13.clues["progress"]+= 1
delilah.cd[0] = 1
quest13.progress()
That should allow you to progress the story until there is an official fix to this. USE THIS AT YOUR OWN RISK, & DON'T FORGET TO SAVE & BACK UP YOUR GAME BEFORE TRYING THIS.