Repeated pop up window re Authentication

There was no C:\Users<your user>\AppData\ folder on my PC, so this did not work for me. I found a workaround however so the error no longer pops up.

Hi @Elaine Burr, 

Good day, and I appreciate the detailed description of your issue. 

I understand that receiving the "Authentication required… Select Continue" notification repeatedly can be disruptive, even when your Office applications remain functional. Please follow the recommended solutions below in the order they are presented. 

1/ Kindly clear the Office sign-in cache. 

• First, close all Office applications, including Word, Excel, PowerPoint, and Outlook, as well as Teams and OneDrive. Navigate to the following directory: C:\Users<your user>\AppData\Local\Microsoft\ Delete the folders named identitycache and oneauth if they are present. Afterward, reopen an Office application and complete the sign-in process once. 

2/ Remove saved Office credentials 

1. Open the Control Panel, select Credential Manager, and then choose Windows Credentials. 
2. Remove any entries related to Office, Microsoft 365, Outlook, or OneDrive. 
3. Restart the computer and attempt to sign in again. 

3/ Reconnect the work account 

1. Open Windows Settings, navigate to Accounts, and select Access work or school. 
2. Disconnect the work account, restart the device, and then add the account back.
   

4/ Update the Office suite 

Within any Office application, navigate to File, select Account, and choose Update Now. 

Ensure that the app you are using is up to date. Sometimes, authentication issues can arise from outdated software that may not comply with the latest security protocols.

5/ Registering authentication methods

If you are using services that require multi-factor authentication (MFA), ensure that your authentication methods (like SMS, email, or authenticator apps) are correctly registered. If you encounter issues, you may need to contact your administrator or support for assistance.

Note: security policies often mandate frequent MFA on unmanaged devices or virtual desktops. Additionally, FSLogix token roaming issues in VDI environments can trigger repetitive sign-in prompts. If colleagues share this experience, it likely indicates a broad policy or environmental configuration rather than an individual hardware fault. Contact your IT admin for further investigation if these authentication loops persist. 

Should you have any further questions, please feel free to reach out.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

The repeated “Authentication required” pop‑up is typically caused by a stuck or invalid sign‑in state, cached credentials/tokens, or a blocked Office service that handles online features.

Try these steps in order:

1. Clear Office sign‑in cache on Windows
   1. Close all Office apps (Word, Excel, Outlook, etc.).
   2. Go to C:\Users\<YourUserName>\AppData\Local\Microsoft.
   3. Delete the folders named identitycache and oneauth.
   4. Reopen an Office app and sign in again when prompted.
   This removes stale identity and token data that commonly cause repeated authentication prompts.
2. If using Outlook on Windows and it keeps asking for a password
   1. Open Control Panel → Credential Manager → Windows Credentials.
   2. Remove any entries related to Outlook, Office, or Microsoft 365.
   3. Restart Outlook and sign in again.
3. If using Office for Mac and prompts mention keychain or “Authentication Expired”
   1. Ensure Office is installed in the default /Applications folder (not moved elsewhere).
   2. Follow the steps in Office for Mac repeatedly requesting keychain access (linked from the article below) to reset keychain permissions.
4. If prompts occur when opening documents with online content or URLs (Mac)
   1. If a proxy is used in the environment, ensure the proxy allows the Microsoft Office user agent.
   2. Add Microsoft Office to the proxy’s exception/allow list so Office can reach its online services without being blocked, which otherwise can trigger repeated auth prompts.
5. If the sign‑in page keeps reappearing when using ADFS (enterprise/federated sign‑in)
   1. Ensure the AD FS 2.0 server has the critical update described in Several issues after you install security update 2843638 or 2843639 on an AD FS server.
   2. This resolves loops where the sign‑in page continually reappears for Microsoft 365 apps.

If the device is managed by an organization, also verify that no policy is disabling required Office connected experiences or blocking the Office sign‑in service, as that can cause persistent prompts.

References:

• How to fix the issue with MS Office asking you to log in every time you open an Office app
• Do you know how to fix the issue where Outlook keeps prompting for a password even though credentials are saved - Microsoft Q&A
• What to try if you can't install or activate Office for Mac
• Office 2016 for Mac 16.x prompts you for authentication when you open a URL
• How to troubleshoot issues that you encounter when you sign in to Office apps for Mac, iPad, iPhone, or iPod Touch when using Active Directory Federation Services