ITMS-90428: Invalid Swift Support

I try to submit a build on the App Store. The upload completes but then I get this email from Apple:

ITMS-90428: Invalid Swift Support - The files libswiftCore.dylib don’t match /Payload/ Make sure the files are correct, rebuild your app, and resubmit it. Don’t apply post-processing to /Payload/

I am building with Xcode 12.4, my Corona version is 2021.3644 and I am on a Mac with Catalina 10.15.7.

Since our last successful app update a month ago, we haven’t changed anything in the app that would justify this sudden error. Any ideas?

Does it have to do with Swift version maybe? I noticed that the libswiftCore.dylib inside our ipa package is version 5.0.1 . I found the same file in various locations inside xCode folder, some are 5.0.1 and others are 5.3.3.

Do you have ability to download Xcode 13.1 and try the latest build with it?

I was hoping there would be some other solution at this point. Upgrading to Big Sur and messing with Xcode just before our scheduled update is a bit risky. Is there anything else we can try?

I’m not sure at this point. I’m already using macOS Monterey. It is possibility something wrong with signing overall but I don’t have any old macOSes

I managed to fix it without updating xCode.

I went to xCode Build Settings --> Swift Compiler Language --> Swift Language Version and set “Swift 5” under the app’s name. It was “Unspecified” before but it worked fine till now.