After upgrading to macOS 26, I noticed that showing a Quicklook preview in my app is very slow. Showing small text files is fine, but some other files I've tried, such as a Numbers document, take about 30 seconds (during which the indeterminate loading indicator appears) before the preview is shown. When showing the preview of an app, such as Xcode, the panel opens immediately with a placeholder image for the Xcode icon, and the actual Xcode icon is shown only after about 25 seconds. During this time many logs appear: FPItemsFromURLsWithTimeout timed out (5.000000s) for: file:///.file/id=6571367.2/ (/) FPItemsFromURLsWithTimeout timed out (5.000000s) for: file:///.file/id=6571367.23684/ (/Users) FPItemsFromURLsWithTimeout timed out (5.000000s) for: file:///.file/id=6571367.248032/ (/Users/n{9}k) FPItemsFromURLsWithTimeout timed out (5.000000s) for: file:///.file/id=6571367.248084/ (/Users/n{9}k/Downloads) Failed to add registration dmf.policy.monitor.app with error: Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named com.apple.dmd.policy was invalidated: failed at lookup with error 159 - Sandbox restriction." UserInfo={NSDebugDescription=The connection to service named com.apple.dmd.policy was invalidated: failed at lookup with error 159 - Sandbox restriction.} Failed to register application policy monitor with identifier 69DDBDB4-0736-42FA-BA7A-C8D7EA049E29 for types {( applicationcategories, websites, categories, applications )} with error: Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named com.apple.dmd.policy was invalidated: failed at lookup with error 159 - Sandbox restriction." UserInfo={NSDebugDescription=The connection to service named com.apple.dmd.policy was invalidated: failed at lookup with error 159 - Sandbox restriction.} FPItemsFromURLsWithTimeout timed out (5.000000s) for: file:///.file/id=6571367.155797561/ (~/Downloads/X{3}e.app) It seems that Quicklook tries to access each parent directory of the previewed file, and each one fails after 5 seconds. Why is Quicklook all of a sudden so slow? It used to be almost instant in macOS 15. I created FB20268201. import Cocoa import Quartz @main class AppDelegate: NSObject, NSApplicationDelegate, QLPreviewPanelDataSource, QLPreviewPanelDelegate { var url: URL? func applicationDidFinishLaunching(_ notification: Notification) { let openPanel = NSOpenPanel() openPanel.runModal() url = openPanel.urls[0] QLPreviewPanel.shared()!.makeKeyAndOrderFront(nil) } override func acceptsPreviewPanelControl(_ panel: QLPreviewPanel!) -> Bool { return true } override func beginPreviewPanelControl(_ panel: QLPreviewPanel!) { panel.dataSource = self panel.delegate = self } override func endPreviewPanelControl(_ panel: QLPreviewPanel!) { panel.dataSource = nil panel.delegate = nil } func numberOfPreviewItems(in panel: QLPreviewPanel!) -> Int { return 1 } func previewPanel(_ panel: QLPreviewPanel!, previewItemAt index: Int) -> QLPreviewItem! { return url as? QLPreviewItem } }

My app (FindAnyFile) provides a Finder-like interface in which it also offers a QuickLook preview command, which invokes [[QLPreviewPanel sharedPreviewPanel] makeKeyAndOrderFront:nil]; Now, if it shows .abcdp files, it often, but not always, crashes. This has been happening for many macOS versions, at least since 10.15, up to 26.1. Also, it does not seem to matter which SDK/Xcode I build with, as I used several and all versions lead to the crash. The issue rather appears to be inside the QLplugin for the AB file (ABCardCollectionView etc.). I am able to trace this crash in Xcode. There are a LOT of errors and warnings coming up, and eventually the qlplugin throws an ObjC exception which in turn brings down my entire app (and here I thought that the XPC system was designed to expressly avoid such crashes). Possibly significant errors are: CNAccountCollectionUpdateWatcher 0x6000025cf800: Update event received, but store registration failed. This event will be handled, but the behavior is undefined. Error using remote object proxy when fetchAnonymousXPCEndpoint: Error Domain=NSCocoaErrorDomain Code=4097 "connection to service named com.apple.telephonyutilities.callservicesdaemon.callstatecontroller" UserInfo={NSDebugDescription=connection to service named com.apple.telephonyutilities.callservicesdaemon.callstatecontroller} connection to service named com.apple.coreduetd.people … CNPropertyNotFetchedException: A property was not requested when contact was fetched. I've attached the (mostly) complete console output from such a debug run. I have also an open bug report regarding this kind of crash (back then I was not able to reproduce it myself): FB15553847 Also, when I "Quick Look" the same file in Finder, I get a "Preview not permitted" for the same items that crash in my app. If I copy the same items to the Desktop, then Finder can QL them and my app doesn't crash when viewing the item on the Desktop. So, the crash only happens with the items inside ~/Library/Application Support/AddressBook/Sources/…/Metadata/. Now, here is the weirdest part: You might think: So, if the Finder shows "Preview not permitted", then my app trying to view those items is the result of that condition (even if that's not supposed to crash). However: I have a clean 26.1 install (in an Apple ARM VM) where Finder also says "Preview not permitted" for these items in the user's Library/AB/Metadata folder, but my app can QL those items without crashing! Also, I have one user who uses 26.1 and gets the crash with files in the same location. So, the "Preview not permitted" is probably not the cause of this crash, though it's suspicious that a user gets this at all - why can't a user QL the abcdp files in the Metadata folder but when copied to the Desktop, QL works? You'd think that Finder has the necessary entitlements to access the AB, or doesn't it? Of course, my app has permission enabled under Privacy & Security / Contacts (if it's disabled, then the app can't show anything but will also not crash). And it has the "Address Book" entitlement. Would be nice if this could be looked into and eventually be fixed. Alternatively, I'd welcome any suggestions on how to prevent my app from crashing if the qlplugin throws. But if you look at the stack trace you'll see that there's no method of my own app involved where I could insert an exception catcher. I added code to my previewItemURL delegate method to make sure the NSURL item is readable, and it is, even Of course, apart from the issue with .abcdp files, the QL operation in my app works flawlessly, i.e. I have never received any other crash reports relating to any other QL plugins. QuickLook for AddressBook crash messages

I didn't really find anything in Apple docs on how to debug my extension using Xcode (so not saying it doesn't exist). I found a current Stack post on it, with several devs all stuck. In 2024 someone said run the Preview Extension, select Finder as the test app, then in a Finder window select a file of the correct type and tap space. Nothin happens when I do this (I get the file icon showing). Suggestions most welcome!

I've a QLPreviewController in the detail/secondary section of a UISplitViewController and when the user swipes down, it dismisses the entire split view. Is there a way to prevent this?

SBS ViewPacking add a half a frame to the opposite eye. Meaning if you look all the way right you can see an extra half frame with left eye and vice versa. OU doesn't work at all, the preview just doesn't show a thumbnail and the video doesn't play. Any hints on how to fix this? I submitted a bug report but haven't heard anything.

My PreviewCode app provides QuickLook previews and Finder icon thumbnails for source code files written in many popular programming languages. The only one it doesn't work will with is TypeScript, which typically uses the ts file extension. This is because Apple's CoreTypes bundle maps the ts file extension to its own MPEG-4 Transport Stream UTI. Right now I have two UTIs mapped to the ts extension: the above one and another, com.microsoft.typescript. The question is, how can I tell macOS' Launch Services to favour the latter over the former so that PreviewCode's previewer app extension is called whenever then user QuickLooks a TypeScript file and not (as currently happens) macOS' MPEG-4 previewer? I'd like to code this into PreviewCode or at the very least provide the technique in the response to the many tech support requests I get about this ts mix-up specifically.

It appears that starting with macOS Sequoia, Quick Look Preview extension no longer loads MapKit maps correctly anymore. Map tiles do not appear, leaving users with a beige background. Users report that polylines do render correctly, but annotations appears black. This was previously working fine in prior macOS versions including Sonoma. STEPS TO REPRODUCE Create a macOS app project, with an associated document. Ensure project has a Quick Look preview extension, with necessary basic setups. Ensure that the extension mentioned in (2) must have a MKMapView. Any other cosmetic changes, etc, does not need to be implemented to observe the base issue. Do note that it has been reported that in addition to the map tiles not loading, annotations don't render correctly as well.

I've been using the MacOS XCode Reality Composer to export interactive .reality files that can be hosted on the web and linked to, triggering QuickLook to open the interactive AR experience. That works really well. I've just downloaded XCode 15 Beta which ships with the new Reality Composer Pro and I can't see a way to export to .reality files anymore. It seems that this is only for building apps that ship as native iOS etc apps, rather than that can be viewed in QuickLook. Am I missing something, or is it no longer possible to export .reality files? Thanks.

Hi, I have a document-based SwiftUI multiplatform app, where the document is saved as JSON. Obviously I don't want Quick Look to show the JSON of my file, so I made a Quick Look Preview extension for each platform. The macOS one works… okay, sometimes it's tricky to test and I need to use qlmanage to empty the cache or to show the preview, but it does work. I can even debug it. But the iOS one just never seems to be run. If I show Quick Look in the Files app on iOS, or if I AirDrop a file from my app to my iPhone, it shows as JSON, with an option to open it in my app. If I run the iOS Preview Extension in the debugger and launch the Files app, and then try to use Quick Look in a file there, it shows the JSON and the debugger just stays in the state 'Waiting to Attach'. The preview extensions are not data based; in both of them I have implemented func preparePreviewOfFile(at url: URL) async throws in PreviewViewController.swift. Pretty much the same code except one is using a UIHostingController and the other is using an NSHostingController. The only difference in the Info.plists for the two extensions is that the iOS one uses NSExtensionMainStoryboard while the macOS one uses NSExtensionPrincipalClass. This is how they were set up when I created them from the relevant Quick Look Preview Extension templates. I made a sample project with a much simpler document, UI, etc. and I have the same issue there. The macOS preview works, the iOS one never runs. I have checked that the correct preview extension is embedded in the target for each OS (under Embed Foundation Extensions in the Build Phases) Is there anything I need to do differently in iOS, or anything I might have inadvertently got wrong? Is there a way to run something similar to qlmanage on iOS, since that sometimes seems to help on macOS? Incidentally, I have also added Quick Look Thumbnail extensions, and they work on both platforms.

When viewing an immersive space and I open a spatial photo in Quick Look, which hides the entire app interface to show the photo. Is there a memory limit? If the inmersive space is not active, the application keep the interface.

There a way to use contentCaptureProtected with Quick Look on VisionOS 26? Or exist a way to see a spatial photo with Quick Look without sharing options ?

Similar to the visionOS Spatial Gallery app, I'm developing a visionOS app that will show spatial photos and videos. Is it possible to re-create the horizontal (or a vertical) scrolling functionality that shows spatial photos and spatial video previews? Does the Spatial Gallery app use private APIs to create this functionality? I've been looking at the Quick Look documentation and have been able to use the PreviewApplication to show a single preview, but do not see anything for a collection of files as the Spatial Gallery app presents in the scrolling view. Any insights or direction on how this may be done is greatly appreciated.

Using the iOS 26 beta simulator, I am experiencing a crash using the QLPreviewController. This is easily reproduced using a small sample app and a sample excel file in the bundle. It does work in prior Xcode 16.4 and simulators (18.5). I didn't find any mention of this in Xcode 26 or iOS 26 release notes but I could have missed something. I don't have a spare device to update to iOS 26 and try on a real device so it may just be a simulator issue? Any feedback would be helpful. Thanks. Error: QuickLook/QLHostRemoteViewModel.swift:37: Fatal error: No extensions could be found matching '_AppExtensionQuery(extensionPointIdentifier: "com.apple.quicklook.UIExtensionPoint", predicate: nil, hostAuditToken: nil, extensionPoint: nil, allowsDuplicates: true)' Sample view controller... import UIKit import QuickLook class ViewController: UIViewController, QLPreviewControllerDataSource { var excelFileURL: URL! override func viewDidLoad() { super.viewDidLoad() // Load the Excel file (example: from bundle) if let url = Bundle.main.url(forResource: "file_example_XLSX_100", withExtension: "xlsx") { excelFileURL = url presentPreviewController() } } func presentPreviewController() { let previewController = QLPreviewController() previewController.dataSource = self present(previewController, animated: true, completion: nil) } // MARK: - QLPreviewControllerDataSource func numberOfPreviewItems(in controller: QLPreviewController) -> Int { return 1 } func previewController(_ controller: QLPreviewController, previewItemAt index: Int) -> QLPreviewItem { return excelFileURL as QLPreviewItem } }

we have written a QL preview generator for some 3D data formats not supported by the AR Quicklook generators included in iOS. however, we are struggeling with the 100 MB memory ceiling imposed on an app extension in iOS. we have included the "Increased Memory Limit" entitlement in both the app and in the preview extensions. nevertheless, the preview generator is limited to 100 MB, even on most recent devices like iPhone 16 Pro Max. we can even see 100 MB limit when we attach to the process with Xcode. my question: did we miss anything? are there additional steps necessary to obtain the increased memory limit? must we explicitly apply for it? 500 MB would be fine (our preview generator does not load textures). best regards

I developed a quick look preview plugin on MacOS, and want to add some data tracking to understand user usage. However, I'm encountering errors when using network capabilities within the plugin. I want to confirm whether the preview plugin blocks network capabilities.

I'm facing the same problem as addressed in this discussion: After switching from legacy QLGenerators to Preview extensions on macOS I cannot debug the extensions' code in Xcode, anymore: I launch the app with the embedded appex from Xcode in debug mode. When trying to attach to the appex process the following error is reported: Code: 6 Failure Reason: Ensure “AppName Preview” is not already running, and matthias has permission to debug it. User Info: {... } System Information macOS Version 15.4.1 (Build 24E263) Xcode 16.3 (23785) (Build 16E140) Timestamp: 2025-05-12T14:07:14+02:00 I'm using a standard user account (no admin) and might miss some obvious steps. Can someone detail the steps to debug a Preview (or Thumbnail) extension with Xcode 16? For legacy Quick Look plugins I was using "qlmanage", but that's not working on extensions. All the best, Matthias P.S.: Pardon me re-posting my reply as a separate thread, to increase visibility, but I'm quite desperate and couldn't find any solution on the web...

ar quicklook suddenly is grayed out on iphone 15 pro, I bought the phone new recently ot was working great, 2 days ago updated to ios 18.1.4, ar mode kept opening but i started getting a move iphone over surface message and the object wouldn’t detect surfaces correctly, updated to ios 18.5, now when i open quicklook modesl ar is completely greyed out, can someone help me fix or detect the issue thank you

When I launch the Quick Look Preview Extension target in Xcode, an app called Quick Look Simulator opens with an almost empty window: Online I read that the Terminal command qlmanage allows to test Quick Look plugins (which I think were an older format for creating Quick Look extensions), but running qlmanage -p /path/to/previewed/file -c public.text -g /path/to/QuickLookPreviewExtension.appex (where QuickLookPreviewExtension.appex is generated by the Xcode build and is located in the DerivedData folder) gives an error Can't get generator at QuickLookPreviewExtension.appex How can I debug a Quick Look Preview Extension?

I have an iOS app which has an embedded Quicklook Extension that works perfectly - in the Files app on iPad/iPhone I can QuickLook view and edit custom file types without problems. However, when I run the app on a Silicon Mac using Mac Catalyst (or (Made For iPad)) while the Finder does recognise the custom file types (allowing "Open in…" or double-clicking to open) it does not show the Quick Look extension. How do I add Finder QuickLook extension functionality to a Mac Catalyst app? Thanks

Hello, is there a way to implement Continuity Markup in our own apps? (This is what I'm talking about: https://support.apple.com/en-us/102269 , scroll down to "Use Continuity Markup"). Also, why does a QuickLook panel (QLPreviewPanel.shared()) not display the markup options when triggered from my app for png image files in my app's Group Container? Do I need to implement certain NSServicesMenuRequestor methods for that? Sadly, I could not find any docs on that. Thank you, – Matthias