When I activated WPMU Dev Dashboard I get this error below

Hi Guys,

When I activated WPMU Dev Dashboard I get this error below when trying to login to the admin, the front-end still works. The only way to stop it happening is moving the plugin outside of the plugins folder + somehow I managed to make it work with another site by deleting the site from the WPMU Dev Premium members area and then reuploading. This time I am stuck. Any ideas?

Fatal error: Uncaught Error: Call to a member function has_cap() on boolean in /home/wessa27/webapps/produceprovider/wp-content/plugins/wpmudev-updates/includes/class-wpmudev-dashboard-site.php:1686 Stack trace: #0 /home/wessa27/webapps/produceprovider/wp-content/plugins/wpmudev-updates/includes/class-wpmudev-dashboard-site.php(1559): WPMUDEV_Dashboard_Site->get_allowed_users(true) #1 /home/wessa27/webapps/produceprovider/wp-content/plugins/wpmudev-updates/includes/class-wpmudev-dashboard-ui.php(572): WPMUDEV_Dashboard_Site->allowed_user() #2 /home/wessa27/webapps/produceprovider/wp-includes/plugin.php(525): WPMUDEV_Dashboard_Ui->setup_branding('') #3 /home/wessa27/webapps/produceprovider/wp-settings.php(392): do_action('init') #4 /home/wessa27/webapps/produceprovider/wp-config.php(98): require_once('/home/wessa27/w...') #5 /home/wessa27/webapps/produceprovider/wp-load.php(37): require_once('/home/wessa27/w...') #6 /home/wessa27/webapps/produceprovider/wp-admin/admin.php(31): require_once('/home/wessa27/w...') #7 {main} in /home/wessa27/webapps/produceprovider/wp-content/plugins/wpmudev-updates/includes/class-wpmudev-dashboard-site.php on line 1686