Bizarre LUA error at bank & home chests

[VulcanTourist]

For several days I've been receiving this error when trying to interact/move items from (and to?) both the bank and home chests:

EsoUI/Ingame/Inventory/InventorySlot.lua:697: function expected instead of nil
stack traceback:
    EsoUI/Ingame/Inventory/InventorySlot.lua:697: in function 'TryBankItem'
    EsoUI/Ingame/Inventory/InventorySlot.lua:1516: in function 'INDEX_ACTION_CALLBACK'
    EsoUI/Ingame/Inventory/InventorySlotActions.lua:96: in function 'ZO_InventorySlotActions:DoPrimaryAction'
    EsoUI/Ingame/Inventory/ItemSlotActionController.lua:30: in function 'callback'
    EsoUI/Libraries/ZO_KeybindStrip/ZO_KeybindStrip.lua:645: in function 'ZO_KeybindStrip:TryHandlingKeybindDown'
    (tail call): ?
    (tail call): ?

This occurs when I try to move items with the default keybind [E]. The error causes this keybinding to become unusable in that context - continues to work elsewhere - and then oddly I am forced to double-left-click on items to move them! This happens with all three of my characters at the bank or any home chest; it does not happen at guild banks.

I am stumped; I presume that it's a mod causing this, but the error offers no clue as to the culprit. I was hoping for some clues to narrow my search more quickly; anyone?


Edit: Apparently there was an initial error and then a slightly different recurring one, and what is above is the latter, this being the former:

EsoUI/Ingame/Inventory/InventorySlot.lua:697: Attempt to access a private function 'PickupInventoryItem' from insecure code. The callstack became untrusted 3 stack frame(s) from the top.
stack traceback:
    EsoUI/Ingame/Inventory/InventorySlot.lua:697: in function 'TryBankItem'
    EsoUI/Ingame/Inventory/InventorySlot.lua:1516: in function 'INDEX_ACTION_CALLBACK'
    EsoUI/Ingame/Inventory/InventorySlotActions.lua:96: in function 'ZO_InventorySlotActions:DoPrimaryAction'
    EsoUI/Ingame/Inventory/ItemSlotActionController.lua:30: in function 'callback'
    EsoUI/Libraries/ZO_KeybindStrip/ZO_KeybindStrip.lua:645: in function 'ZO_KeybindStrip:TryHandlingKeybindDown'
    (tail call): ?
    (tail call): ?

Still inscrutable to me because the error is happening inside of Zenimax's own LUA code... or at least appears to be.

.