Can't submit apps to AppStore: ERROR ITMS-90534: "Invalid Toolchain

Question

ERROR ITMS-90534: \"Invalid Toolchain.

New apps and app updates must be built with the public (GM) versions of Xcode 6 or later, macOS,

Answer 1

If you're looking at this in November 2019, there's an obscure error in Xcode 11.2, which prevents uploading from that version to the App Store. You'll have to upgrade to Xcode 11.2.1, which is currently not available on the Mac App Store yet, but must be downloaded from the Developer Portal here: https://developer.apple.com/download/

The Xcode 11.2 Archive error log even states:

Edit:

Xcode 11.2.1 is now available on the AppStore:

https://apps.apple.com/us/app/xcode/id497799835?mt=12