We recently started implementing Multiple Factor Authentication with office 365 and today I ran into a weird issue while working from home.
Laptop – Windows 10 1703
Outlook 2016 – 16.0.7726.1049
While opening Outlook 2016 I was prompted for my 365 credentials (over and over again) without any MFA prompt.
Would not not go away and would not connect.
So I checked
OWA – https://outlook.office365.com/owa – worked no problem and was prompted with MFA.
Teams – local install, worked no bother with MFA.
So I went to Azure Active Directory and could see loads of failed attempts:
Specifically: User did not pass MFA challenge (non Interactive)
So my guess was Outlook wasnt prompting me for MFA for what ever reason. I tried a new Outlook profile which wouldnt connect and the following registry entried to try and force basic connections from Outlook:
dword value 0
dword value 1
None of this worked so I went all out and did the following which fixed the issue:
- Sign out of Office 365
- Open Word
- In the upper-right corner of the Office 2016 app, click your name, and then click Switch Account.
- On the Accounts screen, click Sign out.
- Locate the account that you want to remove, and then click Sign out.
- Remove the cached credentials in Credentials Manager.
- To do this, follow these steps: Open Control Panel, and then click Credentials Manager.
- Under Windows Credentials, remove all the accounts under Generic Credentials
- Clear cached credentials on the computer from the registry.
- Click Start, click Run, type regedit, and then click OK.
- In Registry Editor, locate and backup then delete the following registry subkey:
4. Launch Word and sign into Office 365 (it logged in without issue)
5. Launch Outlook and I was prompted for my MFA credentials and which I authenticated via my phone and I was in.