When you see the error next time, try to run the following script in an addon like
ZAM Notebook:
Lua Code:
for type, inventory in pairs(PLAYER_INVENTORY.inventories) do
if(type ~= 2) then
for k, v in ipairs(inventory.listView.data) do
if not v.bottom then
df("%d, %d: %s, %s: %s", type, k, tostring(v.data.bagId), tostring(v.data.slotIndex), GetItemLink(v.data.bagId, v.data.slotIndex))
end
end
end
end
The chat output might give some insight into why this happens