Additional Notes: ERROR - build.xml:245: The following error occurred while executing this line:
/tmp/320971.tmp/build.xml:53: The following error occurred while executing this line: /opt/CA/siteminder/adminui/packages/configuration/build.xml:16: genkey returned: 1
It was observed that Hostname and the actual server name don't match hence you are seeing the error.
Fresh installation of the R12.8 SP8 AdminUI by providing all the details including the correct hostname in the AdminUI prerequisite and Adminui resolved the issue.