Some ExtendSync features require third-party cookies to be enabled in your browser.

If cookies are blocked, you may experience loading issues, login failures, or missing functionality inside the add-in.

Google Chrome

Follow the steps below to verify and update your Google Chrome settings.

Option 1: Allow Third-Party Cookies (Recommended)

Step 1: In your Chrome browser, click the three dots in the upper right corner.

Step 2: Go to Settings.

Step 3: Hit Privacy and Security> Third-party cookies.

Step 4: Select Allow third-party cookies.

Step 5: Refresh the browser and reload your Outlook.

Option 2: Keep Third-Party Cookies Blocked but Allow ExtendSync

If you prefer to keep stricter privacy settings, you can still use ExtendSync by adding an exception.

Step 1: In your Chrome browser, click the three dots in the upper right corner.

Step 2: Go to Settings.

Step 3: Hit Privacy and Security> Third-party cookies.

Step 4: Select Block third-party cookies

Add olns.cloudextend.app in the Sites allowed to use third-party cookies section.

Step 5: Refresh the browser and reload your Outlook.

Microsoft Edge

This allows ExtendSync to function even with third-party cookie restrictions enabled.

Option 1: Allow Third-Party Cookies (Recommended)

Open Microsoft Edge.
Click the three dots (⋮) in the top-right corner.
Select Settings.
Go to Privacy, search, and services.
Scroll down to the Cookies and site permissions section.
Click Manage and delete cookies and site data.
Turn OFF the setting:
“Block third-party cookies”
Restart Edge, then reload Outlook.

This provides the most stable ExtendSync performance.

Option 2: Keep Third-Party Cookies Blocked but Allow ExtendSync

If you prefer to keep blocking third-party cookies, you can still use ExtendSync by adding an exception.

Open Edge → Settings.
Go to Cookies and site permissions.
Click Manage and delete cookies and site data.
Select See all cookies and site data (or Manage exceptions depending on Edge version).
Under Allow, click Add.
Enter the following domain:
https://olns.cloudextend.app
Save the exception.
Restart Edge and reload Outlook.

This allows ExtendSync to operate even with stricter tracking settings.

✅ Verify the Fix

After updating your cookie settings:

Open Outlook
Launch the ExtendSync add-in
Confirm the add-in loads fully and functions as expected

If ExtendSync opens and operates normally, the issue is resolved.

Additional Notes

Cookie settings apply per browser profile. Ensure you update the correct profile.
On IT-managed devices, these settings may be locked—contact your IT team if you cannot change them.
Clearing cookies later may require re-adding the allowlist entry.