If using Yanfly Item Durability, The Parry plugin will crash if player attacks with a weapon with 0 durability.
Viewing post in MV - Parry Chance (Shield Block ext.) comments
What normally happens when a player attacks with a weapon with no durability without the parry chance plugin? Does it show a barehanded attack? I feel like a weapon with no durability is replaced with nothing during the attack sequence, causing this error, as it can't get the Parry ignore chance of an item that doesn't exist.
I'll see if I can correct this problem when I get home later.