ROLLBACK of CONVERT not possible for <str>

  Explanation:  The  convert  operation  cannot  be  rolled  back.
  Either no conversion was performed, or the convert operation was
  already committed or rolled back.  Most commonly, this indicates
  that  the  database has already been converted or that the wrong
  version of RMU has been executed.

  User Action:  Use the RMU Show Version command  to  verify  that
  the  correct  version  of  RMU is executing.  Use the RMU Verify
  command to determine if the database has already been converted.