Inconsistent Data Type -ORA-00932

I know there is question related to inconsistent datatypes but that comes from a query. while
I am getting this error on database side when we try to access user defined datatype on our schema that is written in some other schema.
E.g.
we are having xxxtypes schema and we have defined several UDT there. Now in our database we are using xxxtypes.employeeList, so it is throwing following error from that line.

java.sql.SQLSyntaxErrorException: ORA-00932: inconsistent datatypes: expected – got SYSTPzM8RTCHEUy/gQAB/AQBa6A==

EDIT:
Q :Why this error is coming ? and How to overcome this ?

Examples:

create or replace
TYPE InstalmentList IS TABLE OF InstalmentEntry;

   create or replace
   TYPE InstalmentEntry IS OBJECT
   ( 
    reservationinstalment_id NUMBER,
    value NUMBER
   );

We have created above type in xxxtypes schema, to use it for several clients.
Now for a client's database we are using it as :

  SELECT
          column_value AS list,
          rownum AS rownumber
        FROM
          TABLE(
            CAST(
              powermultiset(
                CAST(
                  MULTISET(
                    SELECT
                      rsv_int.reservationinstalment_id,
                      rsv_int.value
                    FROM reservationinstalment rsv_int
                    WHERE
                      rsv_int.reservation_id = p_reservation_id
                      AND
                      rsv_int.payer_type = p_payer_type
                      AND
                      rsv_int.type <> 'r'
                  )
                  AS
                  **xxxtypes.InstalmentList**
                )
              )
              AS
              InstalmentListList
            )
          )
      ) combinations

now xxxtypes.InstalmentList is throwing error saying that it is getting some inconsistent datatypes.