If your subscription fails, you can view the version history.

Viewing Subscription Version History

The version history tab can show you the change history of your subscription with the user and date of the change. If your subscription fails or is running incorrectly, the version history can help identify the cause.

Open your subscription from the Subscriptions tab.
To view the version history, click Version History.
You can click each change entry to view the corresponding subscription code associated with the change.