Hi Lisa,
That object-cache.php file in your wp-content folder is what’s crashing everything — it’s calling a function before WordPress has loaded it, so the whole site (login included) goes down.
Quick fix: log in via FTP or your host’s File Manager, go to public_html/blog/wp-content/, and rename object-cache.php to something like object-cache.php.bak. Site should come back right after.
Once you’re in, disable the object cache from inside the plugin’s settings instead of leaving that file there, and check if there’s a newer version of the plugin that fixes this.
