Unauthorized error

We are using the designer functionality in an iframe inside our application as described in the below reference, Reference : http://docs.esignlive.com/content/c_esignlive_integrator_s_guide/sdk/e_preparing_documents/designer.htm Whenever there is an update to the package, we are creating a Session and Accessing the Designer and loading the same in an iframe inside our application, intermittently we are getting the Unauthorized error when we try to launch the url in iframe. Could this be a conflict because we are requesting the new designer session more often and trying to launch the new session before the old one expires I have attached the screen shot of the error, could you please advise.