MEMBER OF condition causing ORA-00600: internal error code, arguments: [15216], [], [], [], [], [], [], []

I am getting an ORA-00600 when using a MEMBER OF condition using a nested table.

If I create a list from the data in added to the neted table the error does not occur.

OK so I could just use the method that works but this just adds a level of detail to the code and means I am not using what is supposed to be a more efficient method of selecting data.

Can anyone see what might be causing the issue?

The nested table is created as follows
CREATE OR REPLACE TYPE Type_Varchar2_4000 AS TABLE OF VARCHAR2(4000)

The procedure I have created to demonstrate the issue is as follows.

CREATE OR REPLACE PACKAGE BODY REPORT_PKG IS   PROCEDURE testmemberofprc(

            po_ref_cursor OUT RefCursor)   IS
    --TYPE alc_tab IS TABLE OF aggregatelevelright.aggregatelevelcode %TYPE INDEX BY PLS_INTEGER;
    ntt type_varchar2_4000;

    v_sql VARCHAR2(2000);
    v_errcode VARCHAR2(2000);

  BEGIN     ntt := type_varchar2_4000(

'GOR01', 'GOR02', 'GOR03', 'GOR04', 'GOR05',
'GOR06', 'GOR07', 'GOR08', 'GOR09', 'GOR10',
'GOR11', 'FOR', 'LON', 'MOR', 'SWAN', 'NORTH',
'Norwich', 'SOUTH', 'Scotland', 'York', 'ALL');

    v_sql := 'SELECT * FROM IOW_FULL_VW WHERE aggregatelevelcode MEMBER OF :ntt ';

    OPEN po_ref_Cursor FOR v_sql USING ntt;

  EXCEPTION
  WHEN OTHERS

       THEN
       v_errcode := Sqlerrm;

       BEGIN

       v_sql := 'SELECT * FROM IOW_FULL_VW WHERE aggregatelevelcode
IN (' ||


           '''GOR01'', ''GOR02'', ''GOR03'', ''GOR04'', ''GOR05'', '||

           '''GOR06'', ''GOR07'', ''GOR08'', ''GOR09'', ''GOR10'', '||

           '''GOR11'', ''FOR'', ''LON'', ''MOR'', ''SWAN'',

''NORTH'','||


           '''Norwich'', ''SOUTH'', ''Scotland'', ''York'', ''ALL'')';


       OPEN po_ref_Cursor FOR v_sql;

       EXCEPTION WHEN OTHERS THEN
              v_errcode := Sqlerrm;

       RAISE;
       END;

       RAISE;