must  use  the  context  variable,  <str>,   declared   in   the
  STORE/MODIFY.  You had <str>

  Explanation:  You used a context variable in a  STORE  statement
  that  does  not  match  the one declared in the RSE of the STORE
  statement.  For example:  FOR P IN PORT STORE J  IN  PORT  USING
  P.CITY = J.CITY END_STORE END_FOR

  User Action:  Include the correct context variable in your STORE
  or MODIFY statement.