Microsoft 365 Copilot We Could Not Complete Your Request Error: Fix

When you use Microsoft 365 Copilot in Word, Excel, or Outlook, you might see the error message: “We could not complete your request.” This error stops your work and prevents Copilot from generating text, analyzing data, or composing emails. The root cause is often a temporary authentication failure, a network interruption, or a conflict with a browser extension or add-in. This article explains why the error occurs and provides step-by-step fixes to resolve it quickly.

Why Copilot Shows “We Could Not Complete Your Request”

The error appears when Copilot cannot establish or maintain a secure connection to the Microsoft 365 service that processes your request. This failure can happen for several reasons.

Expired or Invalid Authentication Token

Microsoft 365 uses tokens to verify your identity and permissions. If your token expires while you work, or if a token refresh fails, Copilot cannot authenticate your session. The service then rejects the request and returns the error. This is the most common cause in long editing sessions.

Network Interruption or Proxy Interference

Copilot sends data to Microsoft servers for processing. A brief network outage, a strict corporate proxy, or a VPN that blocks certain domains can interrupt this communication. When the service does not receive the request correctly, it cannot process it and responds with the error.

Browser Extension or Add-in Conflict

Extensions in Microsoft Edge, Google Chrome, or other browsers can modify web requests. Ad blockers, script blockers, and privacy extensions may block the URLs that Copilot uses. Similarly, a malfunctioning Office add-in in the desktop app can interfere with Copilot’s operation.

Steps to Fix the “We Could Not Complete Your Request” Error

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

1. Sign out of Microsoft 365 and sign back in
   In the top-right corner of the app or browser, click your profile photo or initials. Select Sign out. Wait 30 seconds, then sign back in with your work or school account. This action forces a new authentication token.
2. Clear your browser cache and cookies
   In Microsoft Edge or Google Chrome, press Ctrl+Shift+Delete. In the dialog, select Cookies and other site data and Cached images and files. Set the time range to All time. Click Clear now. Then close and reopen the browser.
3. Disable browser extensions temporarily
   In Edge, click the puzzle icon in the toolbar and choose Manage extensions. Turn off all extensions. Restart the browser. If Copilot works, enable extensions one by one to find the conflicting one. Common culprits are ad blockers and script blockers.
4. Check your network connection and proxy
   Open a new browser tab and go to www.office.com. If the page loads slowly or fails, your network may be the issue. If you use a corporate VPN or proxy, contact your IT department and ask them to allow these domains: copilot.microsoft.com and all subdomains, login.microsoftonline.com, and graph.microsoft.com.
5. Repair Office installation (desktop app only)
   If you use the desktop version of Word or Excel, close all Office apps. Open Control Panel > Programs > Programs and Features. Find Microsoft 365 in the list, right-click it, and select Change. Choose Quick Repair and follow the prompts. If the error persists, run Online Repair.
6. Reset Copilot settings in the Microsoft 365 admin center
   If you are an admin, go to Microsoft 365 admin center > Settings > Org settings > Copilot. Under Data sources, ensure Microsoft Graph is enabled. Click Save. Then ask affected users to sign out and sign back in.

If Copilot Still Has Issues After the Main Fix

Some users continue to see the error even after following the main steps. The following patterns describe additional causes and their specific fixes.

Copilot Works in One App but Not Another

If Copilot works in Word but fails in Outlook, the issue is likely an Outlook add-in. Open Outlook, go to File > Options > Add-ins. Under Manage, select COM Add-ins and click Go. Uncheck all non-Microsoft add-ins. Restart Outlook. If Copilot works, re-enable add-ins one by one to find the problematic one.

Error Appears Only on a Specific Document or Email

The document or email may contain content that triggers a security filter. Copy the text into a new document. If Copilot works in the new document, the original file had formatting or embedded objects that caused the error. Use File > Info > Document Inspector to remove hidden data from the original file.

Error Occurs After a Microsoft 365 Update

A recent update may have changed a setting or introduced a bug. Go to File > Account > Update Options > View Updates. Check if an update was installed in the last 24 hours. If yes, click Update Options > Disable Updates temporarily and restart the app. If Copilot works, re-enable updates and wait for the next patch.

Item	Quick Fix	Advanced Fix
Authentication token	Sign out and sign back in	Clear browser cache and cookies
Network issue	Check internet connection	Allow copilot.microsoft.com and graph.microsoft.com through proxy
Extension conflict	Disable all extensions	Enable extensions one by one to find the culprit
Office installation	Quick Repair in Programs and Features	Online Repair in Programs and Features

This table summarizes the two tiers of fixes for each root cause. Start with the Quick Fix column. If the error persists, use the Advanced Fix column.

You can now resolve the “We could not complete your request” error in Microsoft 365 Copilot by refreshing your session, clearing browser data, or disabling conflicting extensions. If the error returns, run the Online Repair tool for your Office installation. For persistent issues, ask your IT admin to verify that the required Microsoft domains are allowed through your corporate firewall and proxy.