Applying R12.TXK.C.Delta.6 patch 19330775 failed with following error

Reading driver file (up to 50000000 bytes).
  Patch file system freespace: 91.41 GB
Validating system setup...
  Node registry is valid.
  Application services are down.
  [ERROR] Failed to execute SQL statement :
  declare
  l_msg varchar2(4000);
 begin
  ad_zd_adop.adop_database_validations(l_msg);
  dbms_output.put_line(l_msg);
 end;
  [ERROR] Error Message :
  [UNEXPECTED]Error occurred while performing database validations
[STATEMENT] Please run adopscanlog utility, using the command
"adopscanlog -latest=yes"
to get the list of the log files along with snippet of the error message corresponding to each log file.
adop exiting with status = 1 (Fail)

1. Use the following query to see whether it provides output:

select value from v$parameter where name='_system_trig_enabled'; 

2. If no rows are selected or set as false, then:

Edit the database initialization parameter file to set the value of '_system_trig_enabled' parameter to TRUE as documented in: Note 396009.1.  and retry to apply the patch.

OR

3. Check and correct the node_name in the table applsys.TXK_TCC_RESULTS if it s not showing in the correct case (upper/lower) and retry to apply the patch.

4. Additionally if the above scenarios does not match the case, then run the following (connect  as apps schema in sqlplus) and check the results for more information about the error,

Run the failing sql standalone in sqlplus as apps user as following,

set serveroutput on;
declare
   l_msg varchar2(4000);
 begin
   ad_zd_adop.adop_database_validations(l_msg);
   dbms_output.put_line(l_msg);
 end;
/

Our cases in which this failure could happen:

-> If package AD_ZD_PREP is invalid. This might happen when latest adgrants.sql is not run or some database patches are missing or post install steps of database patches are not run

-> AD_ZD_ADOP or any of the other related AD packages are invalid.

Fix# Run Higher version of adgrants.sql APPS

Our Case the higher version of script from "R12.AD.C.Delta.6 (Patch 19197270)"

19197270/admin/adgrants.sql APPS

And then Compile#

SQL> alter package apps.AD_ZD_PREP compile;

Package altered.

Doc Id# 1993838.1

Good Luck!!