You have no eligible Bundle IDs for Mac OS X apps. Register one here

This issue appears to have reoccured again during the during the first week of January 2020.

This time, it was likely due to an error in the App Store Connect backend where it was not able to fetch the registered bundle ID from Apple Developer backend.

The same was reported to Apple by many developers (including myself) and the fix was applied by Apple on the backend servers.

A relevant discussion on the Apple Developer Forums can be found here:

• https://forums.developer.apple.com/thread/127608

Log out of iTunes Connect and log back in fixed it for me.

This just happened to me (though the error was updated to "macOS apps" - which I'm including here for future solution seekers)

You have no eligible Bundle IDs for macOS apps

It seems that for some reason Mac apps have their own section in the developer portal: switch to it before creating the App ID and it'll appear immediately in AppStoreConnect.