How to Fix Microsoft 365 Network Connectivity Test Tool Fails

The Microsoft 365 network connectivity test tool is designed to diagnose connection issues between your system and Microsoft 365 services such as Outlook, Teams, OneDrive, and SharePoint. It checks network latency, DNS resolution, firewall rules, and connectivity to Microsoft endpoints. However, some users encounter a situation where the Microsoft 365 network connectivity test tool fails, displays errors, or cannot complete the test.

When this happens, it usually indicates a problem with your internet connection, DNS configuration, firewall restrictions, proxy settings, or system network configuration. In some cases, the tool itself may fail due to outdated components or temporary service issues.

Fortunately, there are several troubleshooting steps you can follow to resolve this issue. In this guide, we will walk you through the methods to fix the Microsoft 365 network connectivity test tool failure on Windows 11.

How to Fix Microsoft 365 Network Connectivity Test Tool Fails

Follow the solutions below to identify and resolve connectivity test issues.

1. Check Your Internet Connection

The connectivity test tool requires a stable internet connection.

1. Open a web browser.
2. Visit several websites to confirm internet access.
3. Restart your router or modem if needed.
4. Try switching to a different network.

A stable connection is required for accurate test results.

2. Run the Test Tool as Administrator

Insufficient permissions may prevent the tool from running correctly.

1. Locate the Microsoft 365 connectivity test tool.
2. Right-click the application.
3. Select Run as administrator.
4. Run the test again.

Administrative access allows the tool to perform all required checks.

3. Disable Firewall or Antivirus Temporarily

Security software may block the connectivity test.

1. Open Windows Security.
2. Go to Firewall & network protection.
3. Temporarily disable the firewall.
4. Run the test tool again.
5. Re-enable the firewall after testing.

If the tool works after disabling security software, add an exception for Microsoft 365 services.

4. Check Proxy Settings

Incorrect proxy configuration can block Microsoft 365 connections.

1. Press Windows + I to open Settings.
2. Click Network & internet.
3. Select Proxy.
4. Ensure that proxy settings are correctly configured.
5. Disable the proxy temporarily if not required.
6. Run the connectivity test again.

Incorrect proxy settings can prevent the tool from accessing Microsoft endpoints.

5. Flush DNS Cache

Corrupted DNS cache can cause connectivity issues.

1. Press Windows + S and search for Command Prompt.
2. Right-click Command Prompt and select Run as administrator.
3. Enter the following command:

ipconfig /flushdns

4. Press Enter.
5. Restart your computer.

Flushing DNS clears outdated network information.

6. Reset Network Settings

If the issue persists, resetting the network stack may help.

1. Press Windows + I to open Settings.
2. Click Network & internet.
3. Select Advanced network settings.
4. Click Network reset.
5. Confirm the reset.
6. Restart your computer.

This resets all network adapters and configurations.

7. Update Windows and Network Drivers

Outdated system components can affect connectivity tests.

1. Press Windows + I.
2. Click Windows Update.
3. Select Check for updates.
4. Install any available updates.
5. Update network drivers through Device Manager if needed.

Updated drivers improve network compatibility.

8. Check Microsoft 365 Service Status

Sometimes the issue may be caused by a service outage.

1. Visit the Microsoft 365 Service Health page.
2. Check for any ongoing issues.
3. Wait until Microsoft resolves the problem if an outage is reported.

Service disruptions may affect connectivity test results.

Conclusion

The Microsoft 365 network connectivity test tool may fail due to issues such as unstable internet connections, blocked network access, incorrect proxy settings, DNS problems, or outdated system components. While the failure may seem concerning, it is often related to local configuration issues that can be resolved with basic troubleshooting.

By checking your internet connection, running the tool as administrator, adjusting firewall and proxy settings, flushing DNS, resetting network settings, updating drivers, and verifying Microsoft service status, you can successfully resolve the issue and ensure proper connectivity with Microsoft 365 services on Windows 11.