SAP Message >R021 - Master data for customer &1 is locked (down payment clearing)

Diagnosis
Master data for customer &v1& in company code &v2& is locked.
Down payment cannot be cleared with the receivable in question.

Procedure
Check whether the master data of the particular customer has beenchanged by you or another user.
INCLUDE FICA_NA_INFOADMIN OBJECT DOKU ID TX