In cases where users receive this error message we suggest going through the instructions in this article to ensure you are the owner of the account and using the proper login. This error message you have described is a defect our support is continuing to troubleshoot. In fact, re you attempting to connect a single Mindbody account to multiple Constant Contact accounts? Do you have any spaces or special characters in in your Constant Contact password? If you do we recommend updating those characters our of your password and try connecting again. If you are listed as the account owner and still cannot connect, the second workaround you can try is manually exporting these contacts and upload this file directly into your Constant Contact account.