Thank you for confirming that the issue is on my side. No error messages or codes. Xcode>Settings...>Platforms shows a line above the older Simulator versions and OS's of [iOS17.4 7.23GB (GET)] but the GET button does not do anything. The next line shows [iOS17.4 Simulator 7.23 GB on disk] but none of the three buttons (+ - circle back) at the bottom of the page do anything. On the Xcode Toolbar, the run arrow is crossed and pressing it gives an alert of "Download Xcode support for iOS17.4?" with an subtitle of "iOS must be installed in order to run this scheme", and buttons for "Download & Install" and "Cancel". However, the "Download & Install" button does not do anything. The message in the centre of the toolbar says iOS17.4 Not Installed (GET). Pressing the (GET) button generates a momentary message of "iOS Fetching download information...." under the iOS 17.4 simulator(21E213) Banner. Under the toolbar message of iOS17.4 Not installed, Manage Run Destinations> Simulators gives a blank page with a "No selections" message. I am reluctant to hook up a real device at this point. One comment I saw said this could be a storage issue but my Mac has 266GB unused so I don't think it's that. Activity Monitor show no pressure on CPU or Memory. I know downloads and installs can be lengthy but my usual approachs of watching a movie, or a trip to the garden centre have not worked. Even complete shutdown & restart (couple of times) have not been effective. Hope this provides sufficient information but if something specific sought, just let me know. Any suggestions on what I have missed?

I have seen the same issue since the update. I can make it go away for the duration that I am working on the project by hitting the dismiss option but it comes back if I close and re-open.