I'm trying to import or export the contacts from constant contact using PHP(Drupal) but its giving "Your subscribers could not be exported: Invalid status code 400" error.
In my contact list having 30 contacts at present.
Is there any solution for that, please suggest me to solve the issue.
That error code could be caused by many different things. Could you give me the encoded url that you are using when you try to make this call? It sounds like something in there may be encoded wrong. Please redact your account-specific information if you reply here, or email us at firstname.lastname@example.org.