When users are scoping this app to only one Backlog in Rally, they still get this message "Your request requires access to a workspace or project for which you do not have permission. Contact your subscription administrator to request permission." Even as a Workspace Admin myself, I get the error.
If you experience issues with subscription apps, you are encouraged to open an issue in GitHub, or to correct the issue yourself and create a pull request for it. Rally support can assist you with issues with the subscription catalog itself but not with any of the apps in the catalog.
Release : SAAS
Component : AGILE CENTRAL
The user deleted and redeployed the code for the app and now it works.