To solve this issue, try the following steps:
- Check if the apple certificate (distribution/development) is still valid at developers.apple.com.
- if certificate has expired then create a new certificate.
- download the certificate and double click so that its added to xcode. Verify that certificate is present in xCode.
- Now import this certificate to apple keychain. Go to Keychain, click Login, click Certificates on the top bar, then select the certificate, right click it and export as a p12 file, pay attention to remembering the password.
- Move the p12 file to your Windows machine, go to Tools -> Options->Xamarin ->Apple Account in VS, and click View Details, click Import Certificate, import the p12 file and input the password. Then check if the profile is in %LOCALAPPDATA%\Xamarin\iOS\Provisioning\Profiles