Yep, looks like those errors are from jomsocial,
Warning: include_once(/home/icultiva/public_html/components/com_community/libraries/core.php): failed to open stream: No such file or directory in /home/icultiva/public_html/plugins/user/jomsocialuser/jomsocialuser.php on line 22
Warning: include_once(): Failed opening '/home/icultiva/public_html/components/com_community/libraries/core.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/icultiva/public_html/plugins/user/jomsocialuser/jomsocialuser.php on line 22
Warning: require_once(/home/icultiva/public_html/components/com_community/libraries/featured.php): failed to open stream: No such file or directory in /home/icultiva/public_html/plugins/user/jomsocialuser/jomsocialuser.php on line 23
Fatal error: require_once(): Failed opening required '/home/icultiva/public_html/components/com_community/libraries/featured.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/icultiva/public_html/plugins/user/jomsocialuser/jomsocialuser.php on line 23
I have unpublished jomsocial plugins from your site but you can feel free to uninstall it if you don't use it.
P/S: You might also want to change your "Community" menu item.