Fatal Error when Infinite SEO is activated in Multisite installation

When I attempted to activate the Infinite SEO plugin in my Multisite installation I received the following fatal error (xxxxxx are given for privacy):

Fatal error: Call to undefined function groups_get_groups() in /home/xxxxxx/public_html/xxxxxx.com/wp-content/plugins/wpmu-dev-seo/wds-files/wds-sitemaps/wds-sitemaps-settings.php on line 23

What do I need to do to fix the problem? Thank you in advance for the help.