I had a bunch of emails opened in tabs within YM - things that I needed to deal with today. No I didn't star them - this is just the workflow I use.
A pushy pop-up informed me there was an "update" to YM and that I needed to reload, but it FORCED the reload on me and I lost all of the email tabs that I had open. Either allow the user to postpone the "update", or reopen the email tabs that were open before the refresh!