Startup the database and ran datapatch in Oracle_Home/OPatch (After applying all the DB Patches) $datapatch

 Startup the database and ran datapatch in Oracle_Home/OPatch (After applying all the DB Patches)
$datapatch


[orauat@tos04 OPatch]$ ./datapatch
SQL Patching tool version 12.2.0.0.0 on Sat Apr 11 23:49:14 2020
Copyright (c) 2014, Oracle.  All rights reserved.

Connecting to database...OK
Determining current state...done
Adding patches to installation queue and performing prereq checks...done
Installation queue:
  The following patches will be rolled back:
    20204035 ()
    26609783 (DATABASE PATCH SET UPDATE 12.1.0.2.170814)
  The following patches will be applied:
    21321429 ()
    27264965 ()
    28653113 ()


Error: prereq checks failed!
  patch 26609783: rollback script /u02/orauat/12.1.0/sqlpatch/26609783/21481899/266                                                                                     09783_rollback.sql does not exist
Prereq check failed, exiting without installing any patches.

Please refer to MOS Note 1609718.1 for information on how to resolve the above erro                                                                                     rs.

SQL Patching tool complete on Sat Apr 11 23:50:27 2020