Managing personal Outlook.com account settings, security, and privacy
I was consistently getting the error from December 2017-March 2018 on my computers, so I resorted to the workaround of using a different email address as the primary alias during that time.
In April 2018, I changed my primary alias back to my normal email address and lo and behold, it works again. So it seems that either Microsoft solved the problem (or some other explanation) during that time... at least for my account, using the same computers.