File not open, or incompatible open mode

  Explanation: The program attempted to execute a REWRITE or a DELETE
  statement on a file connector that was not opened, or not opened in
  the correct mode.

  User Action:  You must take the following actions:

      a. Verify the program logic, paying particular attention
         to the open mode.  Consult the description of the valid
         open modes for the REWRITE or DELETE statement, based on
         file organization and access mode.  Refer to the table
         under the OPEN statement in the COBOL Reference Manual
         for this information.

      b. Verify that the OPEN operation was successful.