Exchange 2016 – Hybrid Deployment Check – Invalid Credentials

Thought I would share a weird error I experience in a while with Exchange CU installations. First, let me provide a little background:

  • Exchange 2010 SP3 UR15
  • Hybrid configuration
  • Office 365 tenant with E3 licenses

The client is at the end of their migration of mailboxes to Office 365. We are cleaning up the environment and now installing Exchange 2016 to play the role of hybrid and management. As such, we prepped a brand new server and patched it with the latest Windows patches. I then updated the server with my prerequisites script. The next step was to install Exchange 2016 CU5. During the installation process, the installer recognized that we were in a hybrid mode with Exchange and Office 365. Continue reading