When enabling MailChimp Integration for the first time, after entering the API key, there's an error.
The resulting url is: https://pixie.media/wp/wp-admin/options-general.php?page=mailchimp
And the error output is:
Notice: Undefined index: mailchimp_webhooks in plugins/mailchimp-sync/admin_page.php on line 279
Warning: Cannot modify header information - headers already sent by (output started at plugins/mailchimp-sync/admin_page.php:279) in wp-includes/pluggable.php on line 1171
Lots of gotchas in your software.
Interestingly enough, upon returning to the main plugin page, everything seems fine... until the next error!