I haven't seen the one about Cortana but have gotten the red lettering about WR trying to install something failing because I already had a later version of it already installed.
I've asked Shane about that but as yet, not received an explanation.
I quite often get errors in Event Viewer about certain aspects of Win 10 nor registering for items I don't use, but just ignore them.
I think Win 10 is a particularly difficult program to keep up with because it constantly gets updates for this, that and the other which while not appearing in Update History, they are recorded in reliability history.
I don't know if you want to run WR again and try to make a note of what it reports and I'll inform Shane about it when I have something more specific to report.