Security Policy Errors

How to Fix SharePoint Workflows Returning 401 Unauthorized Access Token Errors

Guest Writer Oct 10, 2026 870 views

Question details

The user is experiencing a 401 Unauthorized access token error when running SharePoint Visual Studio workflows on specific sites, while they continue to work elsewhere.

How to Fix SharePoint Workflows 401 Unauthorized Access Token Errors

Product: Microsoft SharePoint
Device & OS: not provided
Scenario: Running custom Visual Studio workflows across multiple SharePoint sites.
Observed behavior: Workflows fail on selected sites with a 401 Unauthorized error, indicating an access token cannot be retrieved, whereas they execute perfectly on other sites within the environment.

Before you start

Before troubleshooting, ensure you have Site Collection Administrator privileges for the affected SharePoint sites and gather your exact SharePoint version and workflow configuration details.

Solution 1Recommended

Seek Expert Help in the Microsoft Q&A Community

Because access token failures involve complex SharePoint workflow and development configurations, consulting Microsoft's dedicated specialists is the most effective approach.

A 401 Unauthorized error in this context usually points to deep-seated permission issues or expired App-Only tokens that require specialized development troubleshooting.

Gather your configuration details

Note your exact SharePoint version, workflow configuration, the specific affected site URLs, exact error log details, and any recent system or administrative changes.

Navigate to the Microsoft Q&A portal

Open your web browser and visit the official Microsoft Q&A community page.

Draft your support question

Click to ask a new question, pasting all your gathered configuration and error details into the description to give specialists a clear picture of the token failure.

Apply relevant development tags

Ensure you add tags such as 'SharePoint Development' and 'Office SharePoint Workflow' before posting so the right engineers can investigate the issue.

Seek Expert Help in the Microsoft Q&A Community

Community Response Times: Providing comprehensive logs and configuration details in your initial post will significantly reduce back-and-forth communication and speed up the resolution process.

Solution 2

Verify Site App Permissions and Features

Sometimes 401 errors occur because the specific site collection does not have the required workflow app permissions activated or the token has expired.

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Frequently Asked Questions

Why do SharePoint workflows return a 401 error only on specific sites?

This usually happens when site-specific app permissions have been revoked, the token has expired, or the 'Workflows can use app permissions' feature is deactivated on that particular site collection while remaining active elsewhere.

Can I fix access token errors by restarting the SharePoint timer service?

While restarting the SharePoint Timer Service can resolve some general workflow hanging or status issues, 401 Unauthorized errors are specifically related to authentication and token retrieval, which require correcting the permission configurations or App-Only tokens.

What information should I include when posting my workflow error in the Microsoft Q&A community?

Always include your exact SharePoint version (e.g., SharePoint 2016, 2019, or Online), detailed 401 error logs, the URLs of the affected sites, your Visual Studio workflow configuration, and any recent changes made to your farm or tenant.

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