Can't validate and submit an App to the Mac App Store

OK, I have some important pointers (additional to Apples documentation) for people stumbling over similar issues.

1. The error message is totally misleading.
2. Don't take every word in Apples documentation too seriously.

For solving the issue, 2 points have been most significant:

1. Additional to all the other profile-mess you need 2 certificates for submission to the Mac App Store (contrary to the same process for iOS App Store submission). Both have to be installed together with their corresponding public and private key pairs.
   1. Mac App
   2. Mac Installer
2. The codesigning needs to be set on the build target, not the project. I don't remember where but this was described wrong side around in one of Apples documentations.

Eventually my submission worked by keeping to those 2 points.

There is an additional issue with Keychain & XCode.

When Xcode uses a certificate, they want one and only one certificate in your keychain. If you have an expired one, as well as a valid one, Xcode often fails the operation.

So you look at your keychain using Keychain Access, and do not see an expired certificate. It is still there! The default setting for Keychain Access hides expired certificates. Goto the View menu and select Show Expired Certificates. Delete all the expired ones, they are not good for anything.

Quit Keychain Acces and Relaunch Xcode. Xcode often requires a relaunch when adding/deleting certificates.

At that point, the Archive Validate process worked for me.

This is what it was for me as well.

Just want to clarify, you absolutely need both Mac App Distribution and Mac Installer Distribution certificates. Thanks Jacque for your explanation above. It should look like this: