How to fix Outlook, Teams and Office 365 Error Code 800090016

It's to do with your TPM

With the requirements for TPMs coming in full force on Windows 11, it was only a matter of time until there was an issue with it. The error here relates to Windows recognizing your TPM is broken and cannot begin to give you access to your data for protection reasons.

If it is a physical one, it could be as simple as replacing it, but as most are software-based, you’ll need to go through a couple of troubleshooting steps below.

1

How to fix Outlook Error Code 800090016

You’ll want to log off your current account if you’re not in the administrator account and then relog into the admin account to get higher privileges to make some needed changes.

Nex, you’re going to have to go to C:\users\<user account>\AppData\Local\Packages\Microsoft.AAD.BrokerPlugin_cw5n1h2txyewy and you’re going to rename the file you’ve just searched for. Keep it exactly the same – in the event things go wrong – but stick a .old extension on it, indicating to Windows that this is to be ignored.

Log off, restart, then relog back into the account having issues. You might need to sign back into the different services Microsoft provides.

STEP
2

Edit the Registry

You’re going to need to sign out of all Microsoft services for this one – as well as have higher admin privileges, so you can access the registry.

Go to Start and search for Registry Editor and you want to go to HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Common\Identity and find EnableAdal then you need to right-click, edit and change it over to 1.

Under the “Identitities” folder that lives in the Identity one, you want to delete the ADAL Authentication Profile for the specific user having those issues. Reboot and relaunch everything. If you still have issues, you’ll unfortunately have to get in touch with Microsoft.

More on Windows 11

Windows 11 launched October 5th, but as with any new operating system, it’s got some kinks to iron out. Aside from this error, some people have found that having the lack of hardware is causing them issues, with both the community and Microsoft generating ways for users to get around this.

There’s also the matter of needing certain hardware if you don’t want to lose Microsoft’s support. You can see if your CPU and Motherboard match, as well as the best options for upgrading.