At least in the latest core, if account's expansion mode is set from default to AOS (account.Set_UO_Expansion("AOS")), and nothing else is changed, all spellbooks appear empty.

Instead of correct packets 0x24 (Draw Container) & 0x3C (Items In Container), POL sends 0x25 (Add Item To Container) & 0x24 (Draw Container). Especially weird this is because if spellbook is opened using UO::SendViewContainer(), correct packets are sent and spells show up correctly.

Because spellbook's usescript is not started even if set in itemdesc.cfg, fixing this clean way requires hooking doubleclick and handling spellbook in there.

I thought this is still worth reporting.