Thread:Project:Support desk/Can no longer login to my own MediaWiki site, all of a sudden.. Cookie issue all of a sudden../reply

The first thing you should check is if your wiki is sending cookies. You can check that using the developer tools of your web browser, seeing the HTTP traffic and looking for a cookie header. Specially when accessing the login page. You should clear your cookies before accessing it for this purpose, or enter in your browser's "private browsing", to be sure you get the initial cookie.