Other Regular Issues encountered while doing the upgrade could be easily solved using the direct approaches mentioned in the documents referenced with the issues.
https://support.oracle.com/epmos/faces/CommunityDisplay?resultUrl=https%3A%2F%2Fcommunity.oracle.com%2Fthread%2F3880834&_afrLoop=177466743130582&resultTitle=PeopleTools+8.55+-+DPK+-+How+to+restart+a+failed+install+with+%22puppet+apply%22+command+%3F&commId=3880834&displayIndex=1&_afrWindowMode=0&_adf.ctrl-state=ww17d4epq_171
System Error Code 2:
Process Request shows status of 'INITIATED' or 'PROCESSING' but no longer running
HTTP transfer error.
PS_NewStdout: Error opening $PS_HOME/appserv/prcs/<ServerName>/log_output/SQR_XRFWIN_PID/SQR_XRFWIN_PID.log - A file or directory in the path name does not exist. (2)
The solution:
When I deleted the older files, all things came back to normal and the process server started running much better.