I’m developing a file provider extension for macOS; I’m working with xcode 16 and macOS Sequoia. I created an host application via xcode with a simple button “Add domain” that triggers the following code: let domain = NSFileProviderDomain(identifier: NSFileProviderDomainIdentifier(rawValue: "me.piranef.fileprovider"), displayName: "piranef") NSFileProviderManager.add(domain) { theError in NSLog(">>> ERROR: \(theError?.localizedDescription ?? "No error")") } Note: I provide the link to the whole project on GitHub below. Finally I added via xcode a file provider target: At this point everything should be ok to run a simple stub application that once running add a piranef file provider visible under any file manager window in finder. But the following error appears: No file provider was found with the identifier “me.piranef.MyFileProviderTester” My suspect is that despite the target has been created by xcode, some setup in some .plist or .entitlement file must be changed manually or some tricky key added to make the file provider extension visible to the hosting application. I tried to manually change some setup that appeared logical for me like: The product bundle identifier in the target -> build settings of the extension: App Groups in the .entitlements file of the extension that seems set to a placeholder file, set to the same value of the host application: An hint I got reading the readme file of the FruitBasket sample application (by Apple) is to embed without signing the extension into the main app: Done! It’s ok! To give all possible information I uploaded the whole project into my github profile at: https://github.com/fpiraneo/fileproviderstub/ Any hint is welcome; I already googled or searched in StackOverflow or even asked ChatGPT for help but with no results. Even other users are experiencing the same issue and posting on StackOverflow with no answers: "Error adding File Provider domain: No valid file provider found with identifier ‘MyApp.FinderExtensionHost’ on MacOS” on StackOverflow