Hi Vadamalai,
In PFAC type rule number without the preceding word 'AC'. In your case you have to enter 90000002 in PFAC. Also identify the step where the rule 90000002 is under in your workflow. You would have binded values from Workflow container to rule container. Note down the workflow container name.
Now, go into the technical workflow log, click on the workflow container icon, it would show up the container values. Pass the relevant values used in the RULE and simulate the rule from PFAC by entering the values.
Hope you have understood this.
Thanks,
Karthikeyan