A shutdown was triggered, possibly a fatal error was caught. Please note the message below when reporting this.

Array ( [type] => 1 [message] => Uncaught Error: Call to undefined function mb_strtoupper() in /var/www/brad/kesaus.org/wp-content/plugins/amr-users-plus/amr-users-alpha-navigation.php:367 Stack trace: #0 /var/www/brad/kesaus.org/wp-includes/class-wp-hook.php(288): amr_get_index(Array) #1 /var/www/brad/kesaus.org/wp-includes/plugin.php(206): WP_Hook->apply_filters(Array, Array) #2 /var/www/brad/kesaus.org/wp-content/plugins/amr-users/includes/ameta-building.php(371): apply_filters('amr_get_users_w...', Array) #3 /var/www/brad/kesaus.org/wp-content/plugins/amr-users/includes/ameta-building.php(573): amr_get_alluserdata(2) #4 /var/www/brad/kesaus.org/wp-content/plugins/amr-users/includes/ameta-list.php(316): amr_build_user_data_maybe_cache(2) #5 /var/www/brad/kesaus.org/wp-content/plugins/amr-users/includes/ameta-list.php(520): amr_try_build_cache_now(Object(adb_cache), 2, 'user-02') #6 /var/www/brad/kesaus.org/wp-content/plugins/amr-users/amr-users.php(190): alist_one('user', 2, Array) #7 /var/www/brad/kesaus.org/wp-includes/shortcodes.php(32 [file] => /var/www/brad/kesaus.org/wp-content/plugins/amr-users-plus/amr-users-alpha-navigation.php [line] => 367 )