When shutting down Jenkins (e. g. when doing "prepare for shutdown" or "restart after plugin installation), the browser does not update. The screen forever says "Jenkins is shutting down", and even after minutes (while Jenkins is already restarted) it does not update.

This is not smart, as one does not know when Jenkins really is finished shut down. It would be better to at least say "Jenkins is shut down. Please press refresh after it is restarted.".