From my experience, error messages of the sort found across the IndieWeb are symptomatic of early-stage, in development platforms, e.g. those platforms that are still being debugged.
I think that if the IndieWeb is aiming for wide adoption it is time to start designing for the user, not the spec.
I don’t know which generation my website is but I’ve owned a domain and hosted my own website is a teenager. I discovered and added the IndieWeb technology a couple years ago. It was a frustrating experience but I’m appreciative of the work being done. It’s improving.