Resolution:
Ocassionlly, updating to a hotfix or service pack would fail, if the previous update and hotfix were installed on the same day.

This is a known issue # GS-10978 and the workaround for this issue is,

1)On the manager, locate [install dir]/webapps/livecluster/WEB-INF/config/update.[latest hotfix version].
2)Edit the file.
3)At the top of the file you will see the install date. Ensure that it is more recent than the the install date of the previous hotfix/update by incrementing it by one.
Once you saved the file and run it again, you should find you are able to apply the update.