Admin access disappeared

First of all, thank you for the plugin. It reduces headache.

The problem is that even though the plugin works, and the site works, I can’t access the admin page now. I just get a blank page (this is why I can’t say which wordpress version I have). I tried it in several browsers, and the result is the same. I will appreciate any ideas that you might have

Thank you.

The page I need help with: [log in to see the link]