Brizy ashas crash my wordpress site

An add about Brizy has emerged on my wordpress admin page and prevents me to do anything. I can’t get to my Dashboard, I can’t update my plugins, I can’t even install Brizy by clicking the Install Now -button (not that I would want to either). So my Admin site is crashed. What ever I try to do I just get this add.
How can I get rid of it?

Mari

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