Fatal error: Failed opening required '/usr/local/www/index.php' (include_path='/usr/local/etc/inc:/usr/local/www:/usr/local/opnsense/mvc:/usr/local/opnsense/contrib:/usr/local/share/pear:/usr/local/share') in Unknown on line 0
I have not touched the OPNsense configuration since the upgrade. SSH is disabled on the router so the web interface is the only way to manage it.
You and I have encountered exactly the same problem. WebUI 503 Service Unavailable :'(