Login page in blank

Hi! I installed the plugin and seems to work correctly, but after a while, the plugin stops working and when I try to access to the admin, the login page is in blank.

I see that my hosting locks the wp-login.php file and maybe this is because of the stops working. But if I try to block the wp-login.php manually (changing the file permissions), the webpage continues working, and so I am not sure that this is the cause.

Any idea? Thank you.

https://www.ads-software.com/plugins/rename-wp-login/