new to this forum. We downloaded all the C# examples and integrated them into our system. all seems to work - it authenticates and all that fine but we do get the 400 errors when trying to either submit a new contact or delete one from a list. Below is a copy of the xml we are sending. Please note we are not building this out rather we are using the utility classes you have provided us to create the user and do the processing against the API.
<title type="text" />
- <content type="application/vnd.ctct+xml">
- <Contact xmlns="http://ws.constantcontact.com/ns/1.0/">
<ContactList id="http://api.constantcontact.com/ws/customers/MY_CUSTOMER_NAME/lists/4" />
I used your XML through my account and the error I received was that contact list 4 did not exist (in my account, it doesn't). Once I updated that to an existing account, I was able to create a contact without issue. Did you check the error response message to see what the response is? The XML itself is valid and able to create contacts, the only problems I could imagine would be invalid list ID or a 409 Contact Already Exists error in case you are trying to create a contact with a duplicate email address.