- Unfortunately, there has been issues with the latest patch from Microsoft for Outlook 2016.
This issue has caused some users to receive a constant prompt to input their password.
Until an update is released, please try the below 3 fixes to resolve the issue:
3 Options for Fixing the Outlook Credential Popup Error with Office Apps & Office 365 Desktop Application Customers
Option 1: Manually Update/Add mailbox credentials to Credential Manager & rebuild Autodiscover.xml file
1. Go into Control Panel > Credential Manager > Windows Credentials > Remove/delete any records with the users mailbox address.
2. Download the SaveCredentials.exe tool from here
3. Run the SaveCredentials.exe as administrator
4. Enter the mailbox username and password
5. Next navigate to %LocalAppData%\Microsoft\Outlook\
6. Locate the file that ends in Autodiscover.xml
Note: File may look something like this: f0a4256167a8597a89das6hf01c6bb1b - Autodiscover.xml
7. Delete or rename this file.
8. Open Outlook
Option 2: Revert to an earlier version of Office 2016
Go to the following Microsoft article and follow the steps from here:
Option 3: Edit registry to ExcludeExplicitO365Endpoint (do at own risk)
1. Open regedit
2. (Highly Recommended) Create backup (https://support.microsoft.com/en-us/help/322756/how-to-back-up-and-restore-the-registry-in-windows
3. Navigate to HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover
4. Add new DWORD, give it a name of ExcludeExplicitO365Endpoint and value of 1
5. Restart computer
6. Open Outlook, may be prompted once to enter the users credentials.
Please contact support if the issue persists
1300 657 500
Jan 16, 16:45 AEDT