See this:
https://developer.apple.com/forums/thread/732324
gorm
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution
Last seen
User for
Post
Replies
Boosts
Views
Activity
Jory did most of the work, but I think we got it figured out here:
https://developer.apple.com/forums/thread/732324?page=1#756868022
What I think worked:
Followed JoryDeKort's list of 11 steps, above.
I noticed in Activity Monitor that there was still a process with "simulator" in the name, so I thought "let's shut the whole thing down and try again after a fresh reboot".
So I rebooted, then (without opening Xcode), ran "update_dyld_sim_shared_cache" again, got the warning, hit Show In Finder.
Then I opened Xcode 15 beta 2, got the warning again, hit Cancel, and continued getting a series of prompts and I just kept slamming the Cancel button ... and ... voilà, eventually Xcode stopped showing the dialog prompt, the SBOD (spinning beachball of death/mouse activity indicator) spun around for many seconds as I held my breath (I'm sure that was an important step!) and then ... Xcode just opened my project!
I looked in Xcode Settings->Platforms and iOS 17 beta no longer had a Get button, and looked installed.
I changed the Run Destination in Xcode to iPhone 14 Pro (previously, of course, no iOS 17 destinations showed up there, so I was very hopeful), I hit Run, and my app magically appeared in an iOS 17 simulator!!
Hurray! Thank you Jory!