gencharitaci on "[Plugin: Wordfence Security] After enabled falcon engine,"Error 500 - Internal Server Error. ""

My website: http://tinyurl.com/lg4kjsg

I enabled falcon engine for my website and got Error 500 - Internal Server Error. I copied my old .htaccess file and now my website is online.

What could cause this problem ? How can I use falcon engine feature?

https://wordpress.org/plugins/wordfence/