Could you please provide the user ID of the a user who encountered this? Typically, only a guest is present if they have not fully validated their account yet.
We would need to look further into this for you, however the access details on file appear to be incorrect or missing. Could you please update these details by visiting your client area, selecting the relevant purchase, then clicking "Review/Update Access Information" under the "Stored Access Information" section.
We look forward to further assisting you.