Thank you for reaching out to the Community! I'm sorry to hear you are unable to upload your contacts. Are you uploading your contacts from a file? If so, you can click here for the types of files accepted in our system. You can also find some helpful tips on formatting your file here.
If you are still having issues, please email us at social_support(at)constantcontact(dot)com with your username, the contacts you are trying to import, the error message you are receiving, and a reference to this post and we will investigate further!