The Allow Overage on Item Fulfillment preference not be applicable for Lot Numbered or Serialized Inventory Items. This is because a Lot or Serial Number is required when recording Item Fulfillment transactions for Lot/Serialized Inventory Item. This is a validation designed within the system to prevent negative Lot or Serial number quantities.
Should the user want to proceed with the fulfillment, the option is to create a positive Inventory Adjustment designating the same Lot/Serial Numbers that will be used in the Item Fulfillment. In recording the Inventory Adjustment, it is ideal to set the date earlier than the transaction date of the fulfillment transaction.