Hi Priyanka -
I am having the same issue. Also on GRC 10.1 SP10 and simulation works flawlessly, but when inserted into the workflow it does not end in an error, the workflow just stops and does not find an approver.
Were you able to resolve this issue? I may be able to come up with a work-around but would really like to get the Agent rule that I have created working.
Thanks,
Darnell