Hello, Simmers!
I've just joined the SimsWiki lately by answering a question about the Goblins! quest for the Sims Medieval. Turns out, another Wiki user and I were having the same problem! After scrying and binding a shed goblin skin playing as a wizard, the quest will progress, but nothing happens when you send your Sim to the specified location.
Turns out, some Sims can be quite dense when it comes to figuring out which way a force is pulling them. Sending your wizard away from the Cave/Graveyard and then back again should progress the quest further. If that doesn't work, I haven't the slightest clue on how to fix it.
Until next time,
~ Imnurhest