Basically, group lists, member’s groups and other groups pages appear as blank white pages indicating php error. If you view source of the page, you see the HTML is cut off just after some of the fields.
This is the fatal php error
PHP Fatal error: Call to undefined function bp_get_activity_directory_permalink() in /public_html/wp-content/plugins/buddypress-media/app/main/controllers/template/rt-template-functions.php on line 2828
Rolling back to rtMedia 3.7.27 solved the issue.