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Go on the Apple certificate page:

https://www.apple.com/certificateauthority/

Download the Apple Intermediate Certificates

Apple IST CA 2 - G1 Certificate (direct download)

Double click the downloaded certificate to install it in Keychain Access.

You should see it now, in login certificates.

froglady12 wrote:

I receive a message SSL error has occurred and secure connection to the server cannot be made. I have also had difficulties signing on to icloud.

If you can't connect or sign in to iCloud - Apple Support