Change
/nomodkey /shift /itemnotify ${Corpse.Item[${i}].InvSlot} ${WhichButton}mouseup
to
/nomodkey /shift /itemnotify loot${i} ${WhichButton}mouseup
so that it works with modern MQ. Adjustment made to Line 314.
Ton of people ask for help with this issue, mostly from EMU, but it would apply to live as well. Exception is that people on live can simply use an alternative. However, there isn't really an alternative for EMU at the moment.
There's other portions of the code that use .InvSlot which won't function. Such as SellToVendor and DepositToGuildBank. But I've only addressed the issue with the looting.