Error during open of multifile tape

  Explanation: The system produced an error when attempting to open
  a file that is present on a multiple file tape.

  User Action:  You must take the following actions:

      a. Check that the correct tape is in the tape drive.

      b. For files opened for input, check that the file indicated
         by its position exists on the tape.  Use the DCL command
         DIRECTORY and count the files that are displayed.

      c. For files opened for output, verify that the file position
         specified in the APPLY clause makes the file the last one
         on the tape and that all previous files exist.