The gear recommendations for a Frost Mage seem a little bizarre. It is recommending I replace my Astralaan Headdress of the Invoker helm with the quest Spectracles item and my Torc of the Sethekk Prophet with my old Drakefist Amulet (neck).
Something is up with that Spectracles item - for now exclude it from the optimizer and I think that fixes the issues. @yellowfive, who writes the optimizer code, would have to look as to why the optimizer gets stuck on it. He’s on vacation right now, though.