ORA-01031: insufficient privileges

At my client site, Auto Invoice was slow, so I took trace of “Autoinvoice Import Program”. In trace file I found following sql statement

INSERT INTO RA_INTERFACE_ERRORS
  (INTERFACE_LINE_ID,MESSAGE_TEXT
  )
 SELECT l.interface_line_id
,:b0
   FROM ra_interface_lines_gt l
  WHERE (((((l.request_id       =:b1
AND l.customer_trx_id          IS NOT NULL )
AND NVL(l.interface_status,'~')<>'P')
AND l.line_type                 ='FREIGHT')
AND l.link_to_line_id          IS NULL )
AND 1                           <
  (SELECT COUNT(DISTINCT d.code_combination_id)
     FROM ra_interface_lines_gt l2
  , ra_interface_distributions d
    WHERE (((l.customer_trx_id=l2.customer_trx_id
  AND l2.line_type            ='FREIGHT')
  AND l2.link_to_line_id     IS NULL )
  AND l2.interface_line_id    =d.interface_line_id)
  ));

When I do explain plan either in sqldeveloper or TOAD, it would give ORA-01031 error. Explain plan for other queries was working fine. After spending some time, I found that


I do not have insert privilege on RA_INTERFACE_ERRORS and that is why explain plan gives error. If a remove just insert statement then I can get plan for the SELECT statement.