Hi, I am getting the same error. If I disable the plugin then I lose the error message.
PHP Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘WPMailSMTP\\tgmpa_load_bulk_installer’ not found or invalid function name in /var/www/cloudappinc/pppp/wp-includes/class-wp-hook.php on line 286
