I have just been having the same problem as BusinessBloomer, and was able to backtrack through my history to disable the plugin thankfully.
I set the plugin to active (on), and it seemed to work perfectly fine, in the fact that the website was showing ‘under construction’. I could still access the wp-admin login page perfectly fine, but now when I enter my credentials, nothing happens. The page will try and load, and your login will fail, but with no “cannot login” warning of any sort, just refreshes and leaves you login name intact.
