Hi Ralph70
i think the "Error" in Healthchecker was not mentioned because the article was published a day before the Healthchecker script was adjusted (see https://github.com/microsoft/CSS-Exchange/commit/dfa9bee72970f1daa9bc775066af5c002534d7fd)
The Healthchecker script checks if AugSUv1 KB is installed and OS language is not English and if so prints the error.
Regarding that "try and error is not yours": I'm relatively new to this whole Exchange Administration space and find the information found in this tech community very helpful. Some people (like myself) have a lab/test installation where they can easily test something and give others valuable feedback who cannot test it themselves.
I personally think that for this free-to-use service, a 3-hour resolution time for a non-business-critical issue is a great thing.
Best,
Julian