Greetings. Thanks for support. I have resolved the problem, its actually the cron setup. I have new manual cron setup to my server now.
Sill have to solve two questions:
1. how to change slug of my invitation page from http://www.your-domain.com/username/wp-social-invitations/ to http://www.your-domain.com/username/invite-friends/
2. I want to hide it from bp profile tab when Mr.X visit Mr.Y's. I am using this code to my function.php for hiding other tabs. But it doesn't seems to be working for this tab.
//Member Friends Only//
Thanks for all the support you provide for free. Keep up the good work.