Hi, we just recently upgraded from v17 and part of our existing code need to be run at time the backstage closed. We used to subscribe to the Unloaded event of Backstage to achieve it, however since the upgrade, looks like it's no longer fired. Furthermore we've encountered strange behaviour that both Unloaded and Loaded fired when we open up the Backstage instead. Not sure there's a behaviour changes for closing the Backstage in the new version, if that's the case, what would be the recommended way to achieve it? Thanks.