I can't log into the NA server after updating to this newest patch. Finally found the above message in the newest host.developer.log located in my (C:)\Program Files (x86)\Zenimax Online\Launcher.
I ran the game's repair too, but it's not correcting this error. And for some reason, I can't do a restore point either.
I don't know where to look for further information on this or not certain how to add the missing Registry Key back.