Bad List ID Being Included in a Contact's List of Lists
The attached XML includes a list id that doesn't exist for the given customer. (List ID: 1017771550). I'm not sure how this is even possible but I'm guessing the list was deleted and this List ID was never cleared.
Would it be possible for you to purge this list assignment for the contact?
Re: Bad List ID Being Included in a Contact's List of Lists
Thank you for reaching out about this! What you have run into is a minor data corruption that has happened with this contact's list subscriptions. It has no impact on your ability to use this contact through our UI or in sending campaigns, but it can cause the problem that you are experiencing in the API.
I have reached out directly to the team that maintains our Contact Management platform and they should be able to have this data cleaned up for you in the next day or two at the most. If there are any other issues you are running into, please let us know!