Can no longer log into Messages in Mojave or High Sierra
This just started happening a couple days ago, but Message now always reports back an error when trying to log into my Apple ID account, both on my Mojave system and on my High Sierra system.
Messages works just fine on Catalina, both on my 2012 MacBook Pro and my 2012 Mac Pro; it's only with pre-Catalina OS's.
Is anyone else experiencing this issue?