Hi everyone, I am a beginner in iOS/Swift programming. I'm trying to develop a mobile application that allows to mount a network drive in the iphone Files application via the WebDav protocol. I saw on the internet that WebDav is no longer implemented in iOS because considered deprecated by apple. To accomplish this task, I decided to separate responsibilities as follows: Framework: WebDav (responsible for communication with the WebDav server) FileProviderExtension: FileBridge (Responsible for bridging the gap between the WebDav Framework and the iOS Files app) Main App I also have an AppGroup that includes the main application and the fileproviderextension Initially, to measure the feasibility and complexity of this task, I'd like to make a simplistic version that simply displays the files on my drive in the Files app, without necessarily being able to interact with them. FileProviderExtension.swift: import FileProvider import WebDav class FileProviderExtension: NSObject, NSFileProviderReplicatedExtension { private var webDavService: WebDavService? required init(domain: NSFileProviderDomain) { super.init() self.webDavService = WebDavService(baseURL: URL(string: "https://www.mydrive.com/drive")!) } func invalidate() { // TODO: cleanup any resources } func item(for identifier: NSFileProviderItemIdentifier, request: NSFileProviderRequest, completionHandler: @escaping (NSFileProviderItem?, Error?) -> Void) -> Progress { let progress = Progress(totalUnitCount: 1) Task { do { if let items = try await webDavService?.propfind(path: identifier.rawValue, depth: 1), let item = items.first(where: { $0.itemIdentifier == identifier }) { completionHandler(item, nil) } else { completionHandler(nil, NSError(domain: NSCocoaErrorDomain, code: NSFileNoSuchFileError, userInfo: nil)) } } catch { completionHandler(nil, error) } } return progress } func fetchContents(for itemIdentifier: NSFileProviderItemIdentifier, version requestedVersion: NSFileProviderItemVersion?, request: NSFileProviderRequest, completionHandler: @escaping (URL?, NSFileProviderItem?, Error?) -> Void) -> Progress { let progress = Progress(totalUnitCount: 1) Task { do { guard let service = webDavService else { throw WebDavError.invalidResponse } let data = try await service.get(fileAt: itemIdentifier.rawValue) let tempURL = FileManager.default.temporaryDirectory.appendingPathComponent(itemIdentifier.rawValue) try data.write(to: tempURL) completionHandler(tempURL, nil, nil) } catch { completionHandler(nil, nil, error) } } return progress } func createItem(basedOn itemTemplate: NSFileProviderItem, fields: NSFileProviderItemFields, contents url: URL?, options: NSFileProviderCreateItemOptions = [], request: NSFileProviderRequest, completionHandler: @escaping (NSFileProviderItem?, NSFileProviderItemFields, Bool, Error?) -> Void) -> Progress { // TODO: a new item was created on disk, process the item's creation completionHandler(itemTemplate, [], false, nil) return Progress() } func modifyItem(_ item: NSFileProviderItem, baseVersion version: NSFileProviderItemVersion, changedFields: NSFileProviderItemFields, contents newContents: URL?, options: NSFileProviderModifyItemOptions = [], request: NSFileProviderRequest, completionHandler: @escaping (NSFileProviderItem?, NSFileProviderItemFields, Bool, Error?) -> Void) -> Progress { // TODO: an item was modified on disk, process the item's modification completionHandler(nil, [], false, NSError(domain: NSCocoaErrorDomain, code: NSFeatureUnsupportedError, userInfo:[:])) return Progress() } func deleteItem(identifier: NSFileProviderItemIdentifier, baseVersion version: NSFileProviderItemVersion, options: NSFileProviderDeleteItemOptions = [], request: NSFileProviderRequest, completionHandler: @escaping (Error?) -> Void) -> Progress { // TODO: an item was deleted on disk, process the item's deletion completionHandler(NSError(domain: NSCocoaErrorDomain, code: NSFeatureUnsupportedError, userInfo:[:])) return Progress() } func enumerator(for containerItemIdentifier: NSFileProviderItemIdentifier, request: NSFileProviderRequest) throws -> NSFileProviderEnumerator { return FileProviderEnumerator(enumeratedItemIdentifier: containerItemIdentifier, service: webDavService) } } Here's the code I use to initialize my domain in the main app files: fileprivate func registerFileProviderDomain() { let domainIdentifier = NSFileProviderDomainIdentifier("FileProviderExtension Bundle Identifier") let domain = NSFileProviderDomain(identifier: domainIdentifier, displayName: "My Drive") NSFileProviderManager.add(domain) { error in NSFileProviderManager.add(domain) { error in if let error = error { print("Error cannot add domain file provider : \(error.localizedDescription)") } else { print("Success domain file provider added") } } } I can't get rid of the Error : Error cannot add domain file provider : The operation couldn’t be completed. Invalid argument. I don't know what I'm missing Please help me understand