RBAC "Unable to access data."

I am trying to use the new RBAC functionality in portal.azure.com. For one of my Azure subscriptions, I get the error message "Unable to access data." in the Access/Roles box. For my other Azure subscriptions, I have no error message and the correct Owner/Contributor/Reader roles show up in the Access box.

How do I get this issue resolved for this particular subscription?

Thanks,

Brian