Updating email aliases for users on Office 365 admin portal. After updating around 10 users, the below error started popping up trying to save any changes.
[EXO Outage] NotFound received from
Office 365 Heath page wasn't reporting any issues. Logging out and then back in using another browser didn't help.
I wanted to try making changes using PowerShell and logged on with Connect-ExchangeOnline. As soon as I've done that, the issue went away and I was once again able to change aliases in Office 365 admin portal. Now, this could have been a complete coincidence and the issue was actually a temporary glitch on Microsoft's servers, but I had no way to test that...
Microsoft Office 365 Admin Portal