AAAAAAAAND solved!
File permissions in /var/lib/php/ are all wrong if you are using NginX.
chown nginx:nginx /var/lib/php/session/
chown root:nginx /var/lib/php/wsdlcache/
chown root:nginx /var/lib/php/opcache/
And all works. Please @system , write this in the installation manual regarding to NginX because I’ve literally teared out all my hair until I’ve found this.