i am getting this error while using Constant Contact API java library.
you have given solution of manually moving contact to another list but i am using API.
I want to add existing contact into new list which i have created using Constant Contact API java library.
I have successfully created new list using the v2 API but I want to add existing contact into the
created list but i am getting error.
Thank you for reaching out to Constant Contact's API Support.
You did not mention what error you are getting, but the most likely reason you are having problems is you are using the wrong endpoint. In order to move an existing contact in to a different list you will need to update the contact using a PUT.