I did some searches and I didn\'t find anything that was related to my problem.
I\'m currently trying to implement a Facebook login to my website and I\'m having pro
I assume you mean the PHP SDK?
Sounds like you're not passing the 'state' request variable to your PHP script. Have you read https://developers.facebook.com/docs/authentication/ (specifically the bits and protecting yourself from CSRF?).
Also, I assume this is a typo in your question, but shouldn't your rewrite rule be:
RewriteRule ^webhosting-([a-z_0-9-]+)/$ /view_webhosting.php?**webhosting**=$1 [L]