Fatal error: Failed opening required interfaces

[router]

Hello,
When opening the following
https://192.168.1.1/interfaces.php?if=lan

I get this message
Fatal error: Failed opening required '/usr/local/www/interfaces.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 am running opnsense in virtualbox
How can I fix this?

Thanks

[router]

reinstall fixed it