Steps to Reproduce:
This Phabricator install is configured as "https://phabricator.wikimedia.org", but you are using the domain name "phab.wmfusercontent.org" to access a page which is trying to set a cookie. Access Phabricator on the configured primary domain or a configured alternate domain. Phabricator will not set cookies on other domains for security reasons.
I only want to know why this stuck happened.