outlook 365 calendar does not synch with icloud

Question

Once again Outlook calendar stopped synching with iCloud, making it totally unusable. I have not found a solution in all the things I searched. This seems to happen on a regular basis. Can you give us reliable steps to take to diagnose and fix the problem?

Answer 1

Hi Jim,

This issue is unfortunately a recurring one for many users, and it stems from how Outlook and iCloud communicate through the iCloud for Windows sync engine. When either app updates, or when there’s a change in authentication (like two-factor settings or app-specific passwords), the sync bridge can break silently leaving calendars out of sync without any clear error message.

 

Let’s walk through some reliable steps to help diagnose and fix this:

Check the Basics

Make sure your internet connection is stable.

Confirm that iCloud services are online via Apple’s System Status page.

Ensure your Windows date and time settings are correct.

Update Everything

Open Outlook and go to File > Office Account > Update Options > Update Now.

Open Microsoft Store and check for updates to iCloud for Windows.

Run Windows Update to ensure your system is current.

Verify iCloud Sync Settings

Launch iCloud for Windows.

Sign in with your Apple ID.

Make sure Mail, Contacts, Calendars, and Tasks is checked.

Click Apply, then restart both Outlook and iCloud.

Enable the iCloud Add-In in Outlook

In Outlook, go to File > Options > Add-ins.

At the bottom, select COM Add-ins > Go.

Ensure iCloud Outlook Add-in is checked. If it’s missing, reinstall iCloud for Windows.

Reset the Sync Connection

Sign out of iCloud for Windows.

Choose to remove data from the PC (this keeps a local copy).

Restart your computer.

Sign back in and re-enable calendar sync.

Re-add iCloud Account in Outlook

Go to File > Account Settings > Account Settings.

Remove the iCloud account.

Re-add it using your Apple ID and an app-specific password (required if you use two-factor authentication).

Reset Outlook Navigation Pane

Press Win + R, type:

Outlook.exe /resetnavpane

Press Enter. This can fix calendar visibility issues.

 

Let me know how it goes, Happy to assist!