Hi Albert @DTS Engineer I'm confident that Asset Packs are broken on simulator. let assetPackIsAvailableLocally = try await AssetPackManager .shared .assetPackIsAvailableLocally(withID: assetPack) print("assetPackIsAvailableLocally", assetPackIsAvailableLocally) // prints true let file = try await AssetPackManager .shared .descriptor( for: .init("FileThatExists.png"), searchingInAssetPackWithID: assetPack ) // throws A file descriptor couldn’t be opened for “FileThatExists.png”: No file was found at FileThatExists.png”.

On Device: Another error I'm getting using Xcode scheme option is timeout. Asset Pack is 12 GB iPhone Duo 27.1 Xcode 27.1 Error Domain=NSURLErrorDomain Code=-1001 "The request timed out." UserInfo={_kCFStreamErrorDomainKey=4, _NSURLErrorFailingURLSessionTaskErrorKey=LocalDownloadTask <E28841AE-8856-4EE7-822F-3B6ADCC12F8C>.<1>, _NSURLErrorRelatedURLSessionTaskErrorKey=( "LocalDownloadTask <E28841AE-8856-4EE7-822F-3B6ADCC12F8C>.<1>" ), NSLocalizedDescription=The request timed out., NSErrorFailingURLStringKey=https://xcode:e11fb279c65acd4e5dc4521a87cfbf928ac50ae4f3bddd5f8268b6b3b9bac35e@localhost:52317/assetpacks/Database, NSErrorFailingURLKey=https://xcode:e11fb279c65acd4e5dc4521a87cfbf928ac50ae4f3bddd5f8268b6b3b9bac35e@localhost:52317/assetpacks/Database, _kCFStreamErrorCodeKey=-2102}

Hi Albert, @DTS Engineer I've somehow managed to get the assets packs to not throw an error on the simulator... However, I can not access the files by URL to read them. They do not exist. Some files, I can manipulate directly into Application Support, and other various directories. But not all of them will work that way. I have a large amount of files (Map Tiles) and lots of GBs being used. This is a severe problem. I do not own all of the devices needed in order to take App Store Screenshots. I can not take these screenshots without working Background Assets in the simulator. Please address and esclate.

This doesn't seem to work on device either. Checking for updates failed: The request timed out. The manifest couldn’t be refreshed: The request timed out.

.aar files inside of the folder set in the scheme are not uploadded into the ~/Simulator/App/Staging/Unlocalized/AssetPack directory The path of a resource appears to behave differently on simulator with the scheme asset packs compared to on device downloaded asset packs

Hi Albert, @DTS Engineer My primary concern is: Will support for using Background Assets with a local server in the simulator return? My second concern is that: I can't get background assets to work at all in the simulator. My App is data-intensive, and requires background assets to provide that data in order to function. I require the use of a simulator because I don't have the physical device. I require using the local server because I have multiple asset packs (over 100 GB) setup on a dedicated Mac/pipeline. So unfortunately, running and testing on a physical device is unrelated to my questions and issues. I've confirmed these issues exist with Xcode 27.1 RC 1 iOS 27.0 Simulator iOS 27.1 Simulator Xcode 27.1 iOS 26.5 Simulator iOS 27.0 Simulator iOS 27.1 Simulator SDK: 27.1 (24A94232) Simulators: 27.1 (24A94425), Apple silicon 27.0 (24A434), Apple silicon

Hi Albert @DTS Engineer I've updated my code from os26 -> os27. For some asset packs, I'm getting this error The manifest couldn’t be refreshed: DecodingError.dataCorrupted: Data was corrupted. Debug description: The given data was not valid JSON.. Underlying error: Error Domain=NSCocoaErrorDomain Code=3840 "Unexpected end of file" UserInfo={NSDebugDescription=Unexpected end of file} From this code return try await AssetPackManager .shared .manifest .assetPack(withID: id) Other asset packs will pass this code try await AssetPackManager .shared .ensureLocalAvailability( of: assetPack, requireLatestVersion: true ) But then ultimately fail with this error A download with the ID “Required-AssetPack” failed: Error Domain=BAURLDownloadErrorDomain Code=101 "The download failed because the file size provided does not match what was downloaded." UserInfo={NSLocalizedFailureReason=The download failed because the file size provided does not match what was downloaded.} Xcode 27 iPhone Duo Simulator 27.1

Additionally, it's not clear how the scheme setting is supposed to be used. I set it to a folder that contains multiple compressed and un-compressed asset packs and I'm seeing the asset packs failing to be found.

Yes, the simulator. Between Xcode 26 and Xcode 27, background assets were enabled on the simulator, and you could use a locally hosted asset pack from the url override inside of Settings > Developer and click Development Override This feature appears to no longer be available for any simulator using Xcode 27.1

See: https://developer.apple.com/documentation/backgroundassets/testing-asset-packs-locally#Configure-a-URL-override-in-Developer-settings This is what I see inside of Settings > Developer and click Development Overrides on the simulators

Hi @DTS Engineer, With Xcode 27, there is the new runtime scheme option for serving a local asset automatically. You are correct. Previously, assets had to be served through a server and to configure the local override, on the device, you had to go to Settings App > Developer > Background Assets Override. Then, there would be a text field where you could input your IP address. This page is still available in os27, but the text field is missing and the page is blank. Is it still possible to host asset packs as a local server? And if so, where has the url override moved to? My asset packs are large, and hosted on a dedicated Mac with a pipeline that process everything.

I've seen BackgroundAssets also Simi-reguarly not install firstInstallation asset packs as well

26.4 no longer crashes the app but still fails to fetch the Background Assets with Checking for updates failed: No team ID was specified for the app with the bundle ID _“

Somewhere here I saw that the issue with background assets and the simulator was supposed to be fixed with 26.2. I've just tested 26.3 and am still getting the crash The process lacks a team ID..

One of these two changes fixe my issue. (1) My CoreDataStack was inside of a package, and the package didn't include .macCatalyst inside of the platforms. Adding it fixed the issue. platforms: [ .macCatalyst(.v26), ], (2) Adding managedObjectContext to the view explicitly inside of a sheet .sheet() { View() .environment(\.managedObjectContext, managedObjectContext) }