Regarding the issue when validate the simple macOS app, the errors have gone if I perform Custom Validate and manually select the AppStore profile. I stop using the post script to copy my embedded components into the app's Contents and use Copy Files phase to put those components in the appropriate Destination folder instead, and I can validate and distribute my app successfully. However after uploading to AppStore Connect by Xcode, I receive an email from Apple with the error "The executable 'myApp.app/Contents/SharedSupport/BaseResources.bundle' must be signed with the certificate that is contained in the provisioning profile.". I have a loadable bundle (BaseResources.bundle) which contains some resources such as data files and localizable strings, which are used in my main app, and it does not contain any executable codes so I have removed the CFBundleExecutable key in its Info.plist to avoid an error when validating. I set the same bundle identifier as my main app for my BaseResources bundle target and put it in 'Shared Support' destination in Copy Files phase of my main app's target. When turn on 'Automatically manage signing' I can see that Xcode sets 'Development' for Signing Certificate rather than 'Apple Development'. Is it why Apple reports such code signing error? But if I try to manually set 'Apple Development' for Signing Certificate, I see the same error report from Apple after distributing. I'm not sure how to correctly configure for my non-executable loadable bundle so that App Store Connect can sign it correctly. Should I change its bundle identifier not to be the same with my main app or should I put in different folder than "Shared Support" etc...? Please advise, thanks.

Thanks for your response. I create a very simple macOS app using the default project template and try to validate the archive but Xcode shows the same errors so I don't think this issue relates to my embedded components. Please see the attached file for the error log from the file "IDEDistribution.verbose.log", and I'm using Xcode 16.0. I already create the 'Mac App Store Connect' provisioning profile for my test app's bundle identifier, but I'm not sure how Xcode finds this profile. Can Xcode automatically find it by using my AppleID account in Accounts settings?

Please see full crash report attached below, thanks. MyApp_CrashReport.txt

For more information, according to Apple's documentation  - https://developer.apple.com/documentation/fileprovider/macos_support/synchronizing_the_file_provider_extension?language=objc, it says that "The system can also convert dataless copies to materialized copies, as needed. For example, if the user opens a dataless file, the system calls fetchContentsForItemWithIdentifier:version:request:completionHandler: and saves the file’s content. For a dataless folder, the system calls enumeratorForContainerItemIdentifier:request:error: to enumerate the folder’s content.", fetchContents should be called when I open the file but it seems not work.