Copilot Studio Generative Answers Return Empty Response: Fix

When you build a custom copilot in Copilot Studio, the generative answers feature pulls information from your selected data sources. You may ask a question and receive a blank reply or a generic message like “I cannot find an answer to that.” This problem happens because the copilot cannot locate or access the content it needs to generate a response. This article explains why generative answers fail and gives you the exact steps to restore full functionality.

Why Generative Answers Return Empty Responses

Generative answers rely on the copilot’s ability to search indexed content from sources such as SharePoint, OneDrive, Bing Custom Search, or public websites. When the copilot returns nothing, one of three root causes is at play.

First, the copilot has no data source configured. By default, a new copilot uses only its own topics and knowledge base. If you do not add a data source, the copilot cannot generate answers from your documents.

Second, the copilot lacks permission to read the data source. Even when a SharePoint site is added to the data sources list, the copilot’s service principal must be granted read access to that site. Without this permission, the search returns zero results.

Third, content moderation settings block the response. Copilot Studio includes a content filter that can reject results containing sensitive or restricted terms. If the filter is set to a high sensitivity level, it may block legitimate internal content, leaving the user with an empty reply.

Steps to Fix Generative Answers That Return Nothing

Follow these steps in order. Test after each step to see if the issue is resolved.

1. Check that a data source is configured
   Open your copilot in Copilot Studio. Select Topics in the left navigation. Click the Generative answers node. In the panel on the right, verify that at least one data source is listed under Data sources. If the list is empty, click Add data source. Choose the type you need, such as SharePoint or Bing Custom Search. Save the topic.
2. Verify the data source URL is valid
   For a SharePoint data source, the URL must point to a site collection, not a single document or folder. For example, use https://yourtenant.sharepoint.com/sites/HRDocs rather than https://yourtenant.sharepoint.com/sites/HRDocs/Shared Documents/Policy.docx. Invalid URLs cause the search to fail silently.
3. Grant the copilot service principal read access to SharePoint
   Go to the Microsoft 365 admin center. Navigate to SharePoint and select the site collection you added as a data source. Click Permissions and then Advanced permissions settings. Click Grant Permissions. Enter the name of the copilot’s service principal. The service principal name format is CopilotStudio-{environment-id}. You can find this ID in Copilot Studio under Settings > General > Details. Assign the Read permission level. Save the change.
4. Reduce content moderation sensitivity
   In Copilot Studio, select Settings (gear icon) > Generative AI. Under Content moderation, change the slider from High to Medium or Low. Click Save. Test the copilot again. If answers now appear, the previous filter was too restrictive.
5. Republish the copilot
   After making configuration changes, you must republish the copilot for the changes to take effect. Click the Publish button in the top-right corner. Select Publish again in the confirmation dialog. Wait for the publishing process to complete before testing.

If Generative Answers Still Fail After the Main Fix

Copilot Returns “I cannot find an answer” for every question

This usually means the data source is reachable but contains no relevant content. Check that the SharePoint site or Bing Custom Search index actually includes documents that match the test questions. Upload a few sample documents with clear titles and headings. Wait 15 minutes for indexing. Test again.

Generative answers work in the test pane but not in the published channel

The test pane runs with your user credentials. The published channel uses the copilot’s service principal. If the service principal lacks permissions in the target channel’s context, answers will be empty. Recheck the permission grant step above. Also verify that the copilot is deployed to a channel such as Microsoft Teams or a custom website that supports the generative answers feature.

Answers appear only after multiple retries

This suggests a timeout or throttling issue. The search service may be slow to respond. Reduce the number of data sources to one and test. If performance improves, add sources back one at a time. Consider using a single SharePoint site collection with all relevant documents instead of multiple sites.

Copilot Studio Generative Answers: Data Source Options Compared

Item	SharePoint	Bing Custom Search	Public Website
Content source	Your tenant’s SharePoint sites	Custom Bing index of your specified URLs	Any public URL you enter directly
Permission required	Service principal Read access to site	Bing Custom Search API key	None, but site must be accessible
Data freshness	Near real-time after indexing	Depends on Bing crawl schedule	Depends on Bing crawl schedule
Best for	Internal company documents	Curated public web content	Single public page or blog
Empty response risk	Missing permissions or wrong URL	No API key or empty index	Blocked by robots.txt or paywall

Generative answers in Copilot Studio rely on three core components: a configured data source, correct permissions, and appropriate content moderation. By verifying each of these areas, you can resolve empty response issues. After applying the steps above, run a test with a question that has a clear match in your data source. If the response still fails, check the copilot’s diagnostic logs in Copilot Studio under Analytics > Session logs to see the exact error returned by the search service.