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:
Library/Mobile Device/Provisioning Profiles
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.