I made the mistake of looting Mercer's Plans while grabbing Chillrend way before I started the Thieves Guild questline and it seems to have caused a quest-breaking issue. I just finished the quest Hard Answers and handed the Falmer text rubbing to Enthir, and Karliah said she'd meet me at the Ragged Flagon but I never received the quest and she's not there. So I went looking for her and she's back in Snow Veil Sanctum just chilling in the final room.

I did a bit of research on how to fix it, and it involved returning the plans to Mercer's place, and then making her aggressive and triggering the whole "shot with an arrow" sequence again, which I did twice. One time she remained aggressive at the camp (had to wait a week for her to calm down) and another time she was passive, and after going through the conversation with her I got optimistic as the quest Speaking With Silence triggered... and then somehow completed as I finished the conversation. Hard Answers didn't trigger afterwards, Enthir is back at the College of Winterhold, and Karliah goes right back to Snow Veil Sanctum.

I tried going back through Calcelmo's Lab again (which is now empty of bad guys) and making another copy of the rubbing but activating the tablet does nothing. I'm going to try the first strategy one more time but I'm not optimistic about it.

Apparently there are several glitches revolving around these quests but I guess I got the worst one and if there isn't any known fix I guess I'm stuck. It's not the biggest deal in the world since I wasn't going to use any of the Thieves Guild equipment anyways (I'm a heavy armor dual wielder) but as a completionist this is bugging the hell out of me.

Any solution ideas would be greatly appreciated!