getting error while using workspace manager purge

Hello DBAs, im getting below error while using Oracle workspace manager purge .

SQL> EXECUTE DBMS_WM.PurgeTable('schema.tablename',archive_table => NULL,workspace=>'workspacename',purgeAfter=>TRUE);

BEGIN DBMS_WM.PurgeTable('schema.tablename',archive_table => NULL,workspace=>'workspacename',purgeAfter=>TRUE); END;

   *

ERROR at line 1:

ORA-06550: line 1, column 7:

PLS-00306: wrong number or types of arguments in call to 'PURGETABLE'

ORA-06550: line 1, column 7:

PL/SQL: Statement ignored

im using Oracle 12.1 on exadata x7.