When you want to disable LoginPress default error messages and use WordPress or any other plugin error message. The following filter will help you achieve the task
function loginpress_display_error_messages_callback( $error ) {
$error = false;
return $error;
}
add_filter( 'loginpress_display_custom_errors', 'loginpress_display_error_messages_callback' );
Here $error contains the boolean value false
for remove LoginPress default error messages.