Just loaded Better Security, I've used it before on other sites without issue. However, this site I'm working with is hosted on Godaddy; I only mention it because I suspect this is why it's not working.
I went through the whole list of actions, ticked them off. I left the "change wp-content directory" until last because I suspected (correctly) that it might break the site. It suggested I back up my site. I did. I have no other plugins activated and the install is brand new. I have a new theme installed, but it's a stable premium theme so I doubt that's in play here.
So I changed the "wp-content" to another directory name "ixv811" and the site now returns these errors:
Warning: require(/home/content/34/8757334/html/wp-includes/compat.php) [function.require]: failed to open stream: No such file or directory in /home/content/34/8757334/html/wp-settings.php on line 64 Fatal error: require() [function.require]: Failed opening required '/home/content/34/8757334/html/wp-includes/compat.php' (include_path='.:/usr/local/php5/lib/php') in /home/content/34/8757334/html/wp-settings.php on line 64
I tried deleting all the files and uploading the backed up version, but to no avail.