This occurs on My Dell I3-5378 (I7-7500U) system but not on my Minisforum UM690 (AMD). On latest updates I get Protocol error –> todays latest KDE-LINUX … and update says nothing done. Is this something to do with the Dell?? I did rebuild from the .raw for virgin system but on later update I get the same error.
I get that message when the network is down. So maybe that’s also your case, or the server happened to be down.
OK it did update later. Surprising after days and several failures. Just the wrong chances I guess. Thanks Jinliu!!