DBMS_NETWORK_ACL_ADMIN.CREATE_ACL returns ORA-30992

The problem – issueing CREATE_ACL for a new ACL list results in ORA-30992.

SQL> BEGIN
  2    DBMS_NETWORK_ACL_ADMIN.CREATE_ACL (
  3      acl          => 'acl_********.xml', 
  4      description  => 'Email ACL (*.*.nl + *.*.nl)',
  5      principal    => 'SYSTEM',
  6      is_grant     => TRUE, 
  7      privilege    => 'connect',
  8      start_date   => SYSTIMESTAMP,
  9      end_date     => NULL);
 10    COMMIT;
 11  end;
 12  /
BEGIN
*
ERROR at line 1:
ORA-30992: error occurred at Xpath /acl/ace[1][@start_date]
ORA-01858: a non-numeric character was found where a numeric was expected
ORA-06512: at "SYS.DBMS_NETWORK_ACL_ADMIN", line 252
ORA-06512: at line 2

The solution:
run the same code on the database server directly – no time to investigate as to why I get this error on remote (dba) connection…