I have a similar error, having just installed the Thrive theme and BuddyPress-related plugins. I need the BP Group Documents plugin to work, but I just get an error beginning Fatal error: Uncaught Error: Call to undefined function bp_is_group_forum() in /home3/SITE_NAME_HERE/public_html/wp-content/themes/thrive/buddypress/groups/single/home.php:93
I just checked and the BuddyPress version is 3.1.0.
Grateful for any advice.
