Microsoft O365 Office Applications Log in with a random or wrong email address

Starting around the August time frame, I started having an issue where I would start up Word or Excel office application and find that it had logged in with a random, usually wrong, email address.

I have an office subscription through my business and get updates to office apps periodically.

In my subscription, I have two domains, with several emails in each. For instance, on one domain, I have emails with:

  • jack@domain.com
  • support@domain.com
  • wifisupport@domain.com

On another domain, I have similar addresses:

  • jack@domain2.com
  • support@domain2.com

My computer account is logged into an old email address I used to have on live.com, Microsoft’s older, but still in use Azure Active Directory system.

So naturally, I have all these emails in my Outlook client. I have seen no documentation from Microsoft, but as a developer, it appears that the authentication method may have changed from having each office app handle the authentication internally, to having these credentials now cached in the Windows operating system. Since there is currently no way to mark any credential as “primary”, it seems that the office application may log in using the last credential it sees had been used.

Now, I’m not talking about the last credential you purposely used to log in somewhere. It seems that whatever order Outlook checked my emails could cause a shuffle in credential priority. The result is that if I start an Office application that is licensed using my jack@domain.com, it may automatically connect as wifisupport@domain.com and not allow me to edit my documents.

The main way to tell this is happening is that there is a “Privacy” popup that you’ll get when the app is trying to log in with a credential that does not have a license.

You’ll also get the following:

Sign in to get started with Office. Sign in or create account | I have a product key.

The problem I had, was when I clicked on the “Sign in or create account”, the legitimate account was not in the list. If I tried to log in as a different user, I received:

Error: Another account from your organization is already signed in on this device. Try again with a different account.

Well, this is a quandary.

I opened a ticket with Microsoft. I was told that “Yeah, lots of people are having this issue”. Well guess what, he didn’t have any simple resolution.

SOLVED:

Here’s what I found. You can’t really stop this from happening at this point. However, even though most Office apps will not let you change to the correct credential, Outlook will. So the current workaround is:

  1. When you start your computer, always log into Outlook first
  2. Check the credential by clicking on “File” > “Office Account”
  3. Click on “Switch Account” if needed

Once you have Outlook set to the correct account, the other Office apps seem to take it’s lead.

I hope Microsoft will come up with a better solution than this in a future release.