November 2025

How to Fix Exchange SE ECP 401 Error After Upgrading from Exchange 2019

02 November 2025 - Posted in How To by Rabenherz

So you've upgraded from Exchange 2019 to Exchange SE, and now your Exchange Admin Center (ECP) is throwing HTTP 401 errors. Meanwhile, OWA works fine. Fun times. Here's what happened to us and how we [...] Read more