Distribution certificate / private key not installed

Question

Using Xcode 9.1, after building an iOS app, I want to archive it and upload it to the appStore for beta-testing. But I get the following issue after clicking the button

Answer 1

In my case Xcode was not accessing certificates from the keychain, I followed these steps:

1. delete certificates from the keychain.
2. restart the mac.
3. generate new certificates.
4. install new certificates.
5. clean build folder.
6. build project.
7. again clean build folder.
8. archive now. It works That's it.