At this point Cryptic you need to give out tokens to every character that played the event so they all have 3 tokens. This is really nonsense. You release a broken event, patch it twice, and it's still not working right. And the best recompense you give us is to extend the event and tell us to keep doing it with no…
I've tried to claim it on each of my chars, every one gets the same error: Unable to complete transaction. It's only up for 24 hours. Would be nice to get it before it's gone.
Well it seems to have fixed itself. I have no clue how or why. I made a new character and was playing him for a few hours, swapped to the stuck one and the quest was now unstuck. Sent me to the Harper who gave me the trivia, and then back to Elminster for the coin. No idea how it fixed itself, but it did.
It doesn't tell me who to talk to, it just says "Learn a Fun Fact". The diamond is on Elminster, and when I activate the glowy trail that's where it leads me.