"Invalid Swift Support - The SwiftSupport folder is missing" with Xcode 7.3.1

The root cause of this is that the provisioning profile is ad-hoc and it doesn't create SwiftSupport directory in the ipa. The folder is created using app-store as the export method, so it worked for me when I updated my provisioning profile to app-store.

Reference

I received this same email after uploading an .ipa file to App Store Connect through the Transporter app. The following is where I went wrong: I distributed the app using ad hoc.

The following steps are the solution for my error:

1. Archive app
2. Distribute on TestFlight and the App Store
3. Export
4. Open ExportOptions.plist in the newly created folder from the export.
5. Make sure the method property has the value app-store if you are uploading to App Store Connect/TestFlight like me.
6. Drag and drop the exported .ipa file to Transporter.
7. Deliver your app to upload it.

And that's it!

Original answer here: https://stackoverflow.com/a/62568526/10374366

The solution here was in this answer. We needed to use the new -exportOptionsPlist flag with xcodebuild instead of the older -exportFormat and -exportWithOriginalSigningIdentity flags. The plist just needs to have the method key set to app-store.