Hi @kirti: If I understand this correctly, you have a case where there is a assignment configured in process flow. In the assignment, you have a flow action where the user is presented with a navigation rule and your have configured the action of the navigation rule to open another flow action. If this is the case, are you trying to open the new flow action as modal dialog? Will you be able to share your configurations without config data?

In general opening a modal dialog should work. If you are facing issues, please check logs to see if there are any errors.

Thanks.