Microsoft 365 Copilot Cannot Generate Summary Error: Fix

You try to use Copilot in Word, Outlook, or Teams to summarize a long document or email thread. Instead of a summary, you see an error message saying Copilot cannot generate a summary. This usually happens because of restrictive data access policies, missing licenses, or file format incompatibility. This article explains why the error occurs and provides step-by-step fixes to restore summary generation.

The error stems from how Copilot accesses your content. Copilot needs read permissions on the file or conversation, an active Copilot for Microsoft 365 license, and a supported file format like .docx or .pdf. When any of these conditions fail, the summary feature stops working. You will learn the exact settings to check and the quickest ways to resolve each cause.

By the end of this guide, you can identify the root cause of the error and apply the correct fix in under five minutes. No advanced IT skills are required.

Why Copilot Shows the Cannot Generate Summary Error

Copilot generates summaries by reading the content of your document, email, or meeting transcript. It sends this content to Microsoft Graph and the large language model for processing. The error appears when one of these conditions is broken:

Data Access Permissions and Policies

Your IT administrator can restrict which data Copilot can access. For example, sensitivity labels or conditional access policies may block Copilot from reading specific documents. If the file has a label like “Highly Confidential” with encryption, Copilot cannot read its text. The summary feature fails silently with the generic error.

Unsupported File Format

Copilot in Word only summarizes files in .docx, .pdf, .txt, and .rtf formats. Older formats like .doc or .odt are not supported. In Outlook, Copilot can summarize email threads but not calendar items or contact cards. In Teams, meeting transcripts must be enabled and saved before Copilot can summarize them.

Missing or Expired License

Each user must have an active Copilot for Microsoft 365 license. The license is separate from the base Microsoft 365 plan. If the license was removed, expired, or not assigned to the user, Copilot shows the summary error. Check the Microsoft 365 admin center to confirm license status.

Steps to Fix the Copilot Summary Generation Error

Follow these steps in order. Test the summary feature after each step to identify the exact cause.

1. Verify the file format in Word
   Open the file in Word. Click File > Info. Check the file type listed under Properties. If it is .doc or .odt, convert it to .docx by clicking File > Save As and selecting Word Document (.docx). Close and reopen the file, then try the summary again.
2. Check the Copilot license assignment
   Go to the Microsoft 365 admin center at admin.microsoft.com. Select Users > Active users. Find the affected user and open their account. Under Licenses and apps, confirm Copilot for Microsoft 365 is checked. If it is not, check the box and save. Wait five minutes for the license to propagate, then test the summary.
3. Review data access policies in the admin center
   In the Microsoft 365 admin center, go to Settings > Org settings > Copilot. Under Data sources, ensure the toggle for Microsoft Graph data is turned on. If your admin has set specific scopes, verify the user has access to the SharePoint site or OneDrive folder where the file is stored. For files in Teams, confirm the team is not set to Private with restricted Copilot access.
4. Disable and re-enable the Copilot add-in in Outlook
   In Outlook, click File > Options > Add-ins. Under Manage, select COM Add-ins and click Go. Uncheck Microsoft Copilot and click OK. Restart Outlook. Go back to the same location, check Microsoft Copilot again, and click OK. Try summarizing an email thread.
5. Clear the Microsoft 365 cache in Word
   Close Word. Press Windows key + R, type %appdata% and press Enter. Navigate to Microsoft > Word. Delete the folder named 16.0. This removes cached settings. Restart Word and open the document again. Test the summary feature.
6. Test with a new document in a supported format
   Create a new blank Word document. Type a few paragraphs of text. Save it as a .docx file. Open the Copilot pane and click Summarize this document. If it works, the original file had a format or permission issue. If it fails, the problem is with the license or data access policy.

If Copilot Still Has Issues After the Main Fix

Some failure patterns require different solutions. Check these scenarios if the summary error persists.

Copilot Returns a Summary Error for All Users

If multiple users in your organization see the error, the issue is likely a tenant-wide policy. Contact your IT administrator to check the Copilot data access policy in the Microsoft 365 admin center. The policy may have been set to block all document summarization. The administrator can change the setting under Settings > Org settings > Copilot > Data sources and select Allow Copilot to access all Microsoft Graph data.

Copilot Cannot Summarize a Meeting Transcript in Teams

Meeting transcripts must be enabled before the meeting starts. After the meeting, the transcript must be saved to the meeting chat. Go to the meeting in Teams, select the Chat tab, and look for the transcript. If it is not there, the meeting organizer must enable recording and transcription for future meetings. Copilot can only summarize transcripts that are saved and accessible.

Copilot Returns Generic Output Instead of Tenant-Specific Data

This happens when Copilot cannot find the specific file in your tenant. The file must be stored in OneDrive for Business, SharePoint Online, or Teams, not on a local drive. Move the file to OneDrive and try again. Ensure the file is not encrypted or password protected.

Copilot Summary Error: Common Causes and Quick Fixes

Item	Cause	Quick Fix
File format	.doc or .odt file not supported	Convert to .docx using Save As
License	Missing or expired Copilot license	Assign license in admin center
Data policy	Admin blocked Copilot access to Microsoft Graph	Enable data sources in Org settings
Cache corruption	Stale Microsoft 365 cache in Word	Delete the 16.0 cache folder
Add-in conflict	Copilot add-in disabled in Outlook	Re-enable COM add-in

This table lists the five most common causes of the summary error. Each cause has a specific fix that you can apply without waiting for IT support. Start with the file format check, as it is the fastest to test.

Now you can diagnose and fix the Copilot cannot generate summary error in Word, Outlook, and Teams. Start by checking the file format and user license. If the problem persists, review the data access policies with your IT administrator. For recurring issues, set a reminder to clear the Microsoft 365 cache every three months to prevent stale settings from blocking Copilot features.