Error

Fantastico is not installed at the default location /usr/local/cpanel/3rdparty/fantastico. Either move the Fantastico directory from it’s current location to /usr/local/cpanel/3rdparty/fantastico OR enable ioncube loaders in WHM -> Tweak settings.

Check whether ioncube is installed in the server. If not installed it by following command:
root@server [~]# /scripts/phpextensionmgr install IonCubeLoader

You can also rebuild cpanel's internal php just by running following command.
/scripts/makecpphp

Finally restart cPanel once again