Sign-in & Login Problems

Fix Office Apps Keep Asking for Sign-In and Blocking SharePoint Uploads

WPS Editor Oct 10, 2026 869 views

Question details

The user is repeatedly prompted to sign in to Microsoft Office desktop applications and is simultaneously unable to successfully upload or sync files to SharePoint.

How to Fix Office Apps Keep Asking for Sign-In and Blocking SharePoint Uploads

Product: Microsoft Office, SharePoint
Device & OS: not provided
Scenario: Attempting to work on Office documents locally and sync or upload them to a shared SharePoint repository.
Observed behavior: Office applications continuously display login prompts despite successful sign-ins, and file uploads to SharePoint are blocked or generate sync errors.

Before you start

Verify whether the sign-in loop and upload block occur only in the Office desktop applications or also in Office for the web, as this helps determine if the issue is a local cache problem or an account permission error.

Solution 1Recommended

Clear Cached Windows Credentials

Clearing cached accounts forces Microsoft Office to authenticate a fresh session, which often resolves repetitive sign-in loops and related SharePoint upload blocks.

Over time, authentication tokens stored on your device can expire or become corrupted. When this happens, Office desktop apps may get stuck in an endless authentication loop, which simultaneously prevents secure connections to SharePoint.

Open Credential Manager

Press the Windows key, type 'Credential Manager' into the search bar, and press Enter to open the system settings.

Locate Office Credentials

Click on the 'Windows Credentials' tab. Scroll down to the 'Generic Credentials' section and look for any entries that begin with 'MicrosoftOffice15', 'MicrosoftOffice16', or 'OneDrive'.

Remove the Cached Data

Click the down arrow next to each Office-related credential and select 'Remove'. Confirm the deletion for all relevant entries.

Restart and Re-Sign In

Restart your computer, open Microsoft Word or Excel, and sign in again with your official work or school account credentials when prompted.

Authentication Refreshed: Once signed back in, test the SharePoint upload function to see if the block has been lifted.

Solution 2

Verify Licenses and Test via Web Browser

This solution isolates whether the upload block is caused by a desktop app glitch or an actual account permission issue with SharePoint.

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Frequently Asked Questions

Why does my Office app keep asking me to sign in even after I enter the correct password?

This is typically caused by conflicting cached credentials in the Windows Credential Manager, multiple conflicting accounts signed into the same Office desktop client, or an expired authentication token that the software is failing to clear automatically.

How do I know if my blocked upload is related to SharePoint permissions?

Try logging into the SharePoint web interface and uploading the document directly from your browser. If you receive an 'Access Denied', 'Read-Only', or 'Request Access' message, your account has not been granted the necessary permissions by the site owner.

Can cached data cause Office desktop applications to block uploads?

Yes, corrupted cache files in the Office Upload Center or Microsoft Document Cache can intercept and block file syncs to SharePoint. Resetting the Office cache or using the Credential Manager often resolves the sync blockage.

Login & Account Issues