Dear Ranjan,
You will be facing an issue in the update rule after the upgrade to 7.4,
Issue: RETURNCODE = 4.
Reason, This is not supported in or after BW 7.3, so you will have to do some setting in RSADMIN. You can refer the below link for more details.
http://solveissue.com/note?id=1887091
Thanks
Vijayendra