See https://developer.apple.com/forums/thread/787576?answerId=846523022#846523022 and my follow-up reply.

See this thread: iOS 26 UIKIt: Where's the missing cornerConfiguration property of UIViewEffectView?

All bug reports need to be filed using Feedback Assistant.

Not fixed in beta 3. I was able to build and sign using some manual provisioning but when I try to run I get the same issue shown in post #4 above with the "Could not launch ..." screenshot. I'm running a macOS 15.5 host with macOS 26 beta 3 guest running Xcode beta 3. When I try automatic provisioning, I get an error about the device not being registered. When I click on the Register Device button I get a new error about the device already exists on the team and an error about no profiles being found.

I just ran into this with Xcode 26 beta 3 as well. I just left the "fetching" window running and after a minute or two it started to download the iOS 26 beta 3 components. Be patient.

This issue appears to be resolved with Xcode 26 beta 3. Thank you.

I found the cause of the issue. Hopefully Apple can get this resolved in an upcoming beta release. I filed a bug report: FB18649885 Create a new iOS app project using Swift/Storyboard or Objective-C/Storyboard (I imagine a SwiftUI app would have the same issue). Edit the resulting ViewController.swift or ViewController.m. Import CoreLocation. Then in viewDidLoad, add one line: let coord = CLLocationCoordinate2DMake(40, 40) or CLLocationCoordinate2D coord = CLLocationCoordinate2DMake(40, 40); depending on your chosen language. These are just one of many possible lines of CoreLocation code that will cause the crash. Set the app's iOS deployment target to iOS 16, 17, or 18. Add a Mac Catalyst destination. Build and run the Mac Catalyst destination with Xcode 26 on a Mac with macOS 15 (or earlier I would think). The issue disappears if you have an iOS deployment target of iOS 15. The app will crash on startup due to the missing _LocationEssentials.framework.

Did you find the solution? I just changed my app's deployment target to iOS 17/macOS 14 and I'm now seeing the same issue as you.

You will want review the following thread: Building macOS apps with Xcode 26 on macOS 26 VM

I'm using UIKit, not SwiftUI, but thanks for the pointer. I just filed FB18594783 to make an official request for the symbol to be added.

Your tests have typos. The value of url.path includes com~apple~CloudDoc. Those are tildes, not dashes. Also note that the URL based to openURLContexts is only valid while that method is being executed. Once it returns, the URL is no longer valid.

See https://developer.apple.com/forums/thread/787996

Already discussed here: https://developer.apple.com/forums/thread/789148

The barButtonItem property of UIPopoverPresentationController is deprecated. Use sourceItem which was added in iOS 16.

You submit the macOS binary exactly the same way you submit the iOS binary. I'm not familiar with Unity app development so I can't provide specifics there. If you use the Xcode Organizer to submit the iOS binary to App Store Connect then do the same for the macOS binary. In App Store Connect you need to update your app entry so it has a macOS version. Click on the "Add Platform" link. It will be part of the same app entry as the iOS version. You add screenshots and description and all of the usual metadata to your app but now you will have an iOS section and a macOS section. Under each section you add the appropriate build and submit each for review separately.