How to save Sales return if ‘Invalid Customer Item’ error occurs on done button click?

Cause: System shows ‘Customer item code is not Found in Customer item master for this
customer code.’ or ‘Invalid Customer Item’ error on saving Sales return because the selected item and customer are not mapped in Customer Item Master.
Remedies: User has to map the selected item to customer in customer item master.
Customer Item menu exists in SCM module, SCM Settings, Masters, Customer, Customer Item master.