I've replaced the text for email and username(s) for obvious reasons. I've gone through online similar error some pages suggest a list with over 1000 contacts will not allow new emails to be added, I tried it on a list not used with no contacts and still got the same error when running the code below:
Re: Problem updating contact list using Python API for Constant Contact
Thank you for reaching out to the API Support team here at Constant Contact.
In order to tell you exactly why you may be getting a conflict error, we will need a bit more information. Please email firstname.lastname@example.org with the Constant Contact username and the contact email address you are having trouble adding. Once we have this, we can dig into this a bit deeper and give you a specific reason for that error.
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