Fatal error: Call to undefined function forward_static_call

What version of PHP is your server running?
http://www.wikihow.com/Check-PHP-Version

If it’s lower than 5.3, you’ll need to get your host to update it.

Well the function forward_static_call() doesn’t exist earlier, so the ‘wix-hotels’ plugin won’t work, since it uses it. That’s what’s throwing the error.

5.2 is very very out of date, and insecure, so you should update regardless, if you are still on it.