Orace Applications 12.2.4 version,
when attempting to run adop phase=prepare, the following error occurs:

Steps to reproduce the problem:
- Set the environment variables.
- Execute the command adop phase=prepare.
- The error is shown in the adop log file.
Synchronizing Snapshots failed and that is the root cause for prepare phase failure.
SOLUTION:
Execute the following steps to resolve the issue.
- Execute the following script from SQL command prompt:
begin
ad_zd_adop.sync_snapshots(342);
exception when others then
raise_application_error(-20001,’Error while calling ad_zd_adop.sync_snapshots.’ || sqlerrm);
end;
/
- Execute the adop phase=prepare again.