critical error… | WordPress.org

After recovering a crashed WP blog site – I have been one by one MANUALLY uploading and reinstalling my Plugin Suite with the most up to date version of each one, all was going well… when I brought up AIOSEO [ Version 4.4.1 ] and activated it, my site promptly crashed again with that dreaded message…

“There has been a critical error on this website.”

When I deactivate AIOSEO, the site functions.
None of my plugins are particularly exotic.
Note that there may be an issue with the lack of the ssh2 PHP extension, circumvented with ssh-sftp-updater ver. 0.8.5.

Any help? The pulging is normally quite useful.

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