Cannot Access Admin Panel

Hey everyone,

A few hours ago i worked with a developer on my site and he wanted to access my Plesk admin panel, i sent him the login dates and he tried to login, now we are both no longer able to access it.

Whenever i try to login as admin now, i get redirected to this url: http://example.com:8443/server/create_subscription.php#

Can anyone help me figure out what's causing this?