Actually – I ended up installing the previous version (3.3.5) via FTP and so my post with the review is working again. Let me know when 4.0 is fixed!
So I deleted the WP Review folder via FTP and my site is back up. Fortunately I only had used the review on one post so deleting it was a viable option for me. However, I would like to use it again, but this glitch will obviously need to be fixed for me to install the plugin again.
Same problem – my whole site is down with this error so I can’t uninstall it from WP. Should I delete it from my host’s control panel?