When I attempt to activate the installed Groups plugin from within WordPress the activation fails. The WordPress admin screen immediately displays ONLY the Comments side bar and the Comments admin screen. Reloading the page and even logging out and back in results in the same display. However, attempts to activate Groups via the wp command-line utility (wp plugin activate groups) at least displays the following error:
Fatal error: Call to a member function get_role() on a non-object in /path/to/public_html/WordPress/wp-content/plugins/groups/lib/core/class-groups-controller.php on line 337
The Groups plugin seems to be the solution to my needs, so please let me know what I can do to resolve this problem and get Groups up and running.