imessage

Both my host and VM are on MacOS 15 Sequoia, latest version, so is Parallels. I was able to sign in to iCloud during setup. Later AppStore sign-in fails, and iCloud mail is unavailable, which was expected. However, I cannot use iMessage. Whenever I try to sign in I get "An unknown error...

I installed Parallels 13 on my MacBook Air (High Sierra). Parallels is working fine, but now iMessage doesn't work. It gives me a message, "There was a problem with Messages. You need to quit and open Messages again." Except that that doesn't do anything; the message appears again upon...