Missing iOS Distribution signing identity

Question

I deleted all my provisioning profiles from my Mac by mistake (Library/Mobile Device/Provisioning Profiles). Now, no matter what I do, Xcode gives me this error:

Answer 1

This worked for me: Keychain Access -> View -> Show Expired Certificates

then

Keychain Access -> System tab

Locate the EXPIRED "Apple Worldwide Developer Relations Certificate Authority" certificate and delete it.