Act 3 Rune Quest Bug

I was on the final step of the Act 3 rune quest and entered the Mystic Sanctuary, but I couldn’t see the NPC and was unable to interact with them. After reaching Act 4, I also can’t see the related rune quest. Please help me fix this. Thank you.

Now i can see the NPC,but still can't talk with him

Were you able to open the circular door? If not, you need the find the 3 runes in the area. Venom crypts, Azak bog, and Jungle ruins. Once you find all 3 you can open the door.