I'm not quite sure where the problem is, but I will describe what I am doing to recreate the issue, and am happy to provide whatever information I can to be more useful. I am changing the ActivationPolicy for my app in order to make it unobtrusive when in the background (e.g. hiding it from the dock and using only a menu bar status item). When the user activates the app with a hotkey, it changes from NSApplicationActivationPolicyAccessory back to NSApplicationActivationPolicyRegular. This allows normal usage (dock icon, menu bar, etc.) This works fine, except in a rare situation which I finally just tracked down. If there is a window open in the app and I use the hotkey to convert back to an accessory, and then disconnect and reconnect the display on which the app was previously displayed, when I convert the app back to "regular mode", the menu bar has disappeared (and I am left with an empty space at the top of the screen). I can also trigger this bug by having the display in question briefly mirror the other display (effectively "orphaning" the hidden app), and then restoring the original side-by-side configuration before activating the app again. The app otherwise works, but the menu bar is missing. Switching back and forth with other apps does not fix the problem. Quitting and restarting the app resolves the issue. As does disabling the accessory only mode and forcing the app to always remain in "regular mode" with a dock icon (there is a preference for this in my app). Once fixed, I can then re-enable the "accessory mode" and all is well until the bug is triggered again. The bug would normally occur quite sporadically, presumably requiring a particular combination of changing Spaces or displays, or having the computer go to sleep while this app was in accessory mode. Thus far, the above is the only way I have found that can replicate this issue on demand. If I close all windows before hiding the app, then it works fine when I revert to "regular mode". It only happens if there is a window open at the time. Using applicationDidChangeScreenParameters: on my AppDelegate indicates that there is a change in screen, and logging window.screen.frame for each open window in [NSApp orderedWindows] shows that the size changes from e.g. 1920x1080 to 0x0 and back while the display is disconnected or mirrored. There is also an error in the console in Xcode when this happens -- invalid display identifier <some UUID>. I have tried various options for window collectionBehavior, as well as various settings for Spaces (which I normally use). None of these changes has fixed the behavior thus far. I use [NSApp hide:self]; from my AppDelegate to hide the app, and [[NSRunningApplication currentApplication] activateWithOptions:NSApplicationActivateAllWindows];[NSApp unhide:self]; to bring it back to the front. I welcome any ideas for things to chase down, or requests for more specific information that would be useful. Thank you! Fletcher

I have successfully used the primaryPresentedItemURL functionality of NSFilePresenter in macOS apps to, write to file.foo after the user used, for example, NSOpenPanel to open file.bar in a sandboxed application. This makes use of the primaryPresentedItemURL property belonging to NSFilePresenter (as well as NSIsRelatedItemType in Info.plist). I am struggling to do the same on an iOS/iPadOS app and not sure whether that can be done. primaryPresentedItemURL is not available outside of macOS. When I try to use the same approach as macOS (except for primaryPresentedItemURL of course), it works on the Simulator, but not on an actual device. Can this be done in some other way? My internet search has not revealed a solution. Thanks in advance!!