To enable editing of Invoices that were locked after generating from delivery orders:
Go to Housekeeping, Run Setup, Administrative Tools.
Select Setting.
Select the option Allow edit quantity of invoice generated from DO.
Editing Delivery Orders (DO) and Invoices Already Updated or Attached
To enable editing of Invoices that were locked after generating from delivery orders:
Go to Housekeeping, Run Setup, Administrative Tools.
Select Setting.
Select the option Allow edit quantity of invoice generated from DO.