In every GHNS dialog I've ever interacted with, on every distro, with every plasma version, all of them have displayed an error message on the bottom that says "Unknown Open Collaboration Service API error. (999)". It is reproducible at will just by opening a GHNS dialog on Neon, Kubuntu, Manjaro, etc. There doesn't seem to be any real adverse effect, since the content always loads just fine. We should make this stop, since it makes users nervous and reduces the trustworthiness of KDE software in general and GHNS functionality in particular.
*** Bug 397513 has been marked as a duplicate of this bug. ***
*** This bug has been marked as a duplicate of bug 391111 ***