The title is imprecise but I can't reproduce the problem reliably. However, I've been noticing it for a while, typically after starting my Xfce session (which runs `thunar --daemon`): * new files don't have a thumbnail (typically new downloads made since the start of the session, without having yet opened Thunar once); * reloading the view has no effect; * Tumbler's logs show that no requests are sent to it. Running `thunar -q` then restarting Thunar (in daemon mode or not) solves the problem. I hadn't opened an issue until then because a lot of changes were taking place about thumbnailing, but now that !416 has been merged I think it's time.