I have a user who is unable to log on to Outlook.com. The user's credentials are accepted, but the page redirects to a blank page (URL and embedded error code below).

A little history of this account. The user initially created a Microsoft ID using their "work" email address. Since that time the organization has transitioned on-prem Exchange to Office 365 Exchange Online using ADFS for authentication. The result is that the user's "work" email address is now both his personal Microsoft ID and his Organizational ID.

Logging in to www.outlook.com results in a blank page that has the URL.

https://pod51042.outlook.com/owa/?hm=1&owa=1&f=255&MSPPError=-2147205086

Logging in to https://login.live.com successfully navigates to the user's account administration page.

This can be reproduced on multiple workstations.

I have also created an alias for the user and tried logging in with that address instead. The results were the same.