Message Oracle PLS-00597 - expression string in the INTO list is of wrong type

ERRORexpression string in the INTO list is of wrong type
CAUSEThis exception is raised for the following errors: - the expression in INTO clause of OPEN or RETURNING statement is neither of legal SQL datatypes nor of PL/SQL RECORD datatype - a collection of records is used in INTO clause of OPEN or RETURNING statement. - a record or a collection of records is used in BULK COLLECT INTO
ACTIONUse expression with correct datatype in the INTO clause