My friend and I are playing co-op and we're currently sitting on 5 inert stones, but only the Hall of Heroes has unlocked. We talked to the woman that's supposed to appear in there, but now she's nowhere to be found and we can't talk to Zixzax or do anything.
Is there anything we can do to get her to re-appear, or get Zixzax to talk to us how he's supposed to short of losing out on hours of progress by reloading an old save? The Weaver of Time confirms that we talked to her ["I met a strange woman in one of the other rooms."] and all Zixzax says is something about leaping through the portal, or wondering who awaits us in the next chamber.
The only thing in the environment remotely interactable is one of the top portals "To the Forbidden Zone" but it says the teleporter refuses to work.
