How to Fix Outlook Calendar Not Syncing

What Causes This?

Outlook calendar sync problems usually happen because the app cannot properly connect to your Microsoft 365, Exchange, Outlook.com, or IMAP-linked account. Common causes include a bad internet connection, an outdated Outlook app, a corrupted local cache or offline data file, or account settings that stopped syncing correctly after a password or server change.

In some cases, add-ins or Windows credential issues can also block Outlook from updating calendar changes across devices.

Common Symptoms

• New calendar events appear on one device but not another
• Edited or deleted appointments keep reappearing
• Outlook shows old calendar data and does not refresh
• Shared calendars fail to update or load properly
• You see sync errors, disconnected status, or repeated password prompts

How to Fix It Manually

1. Check that Outlook is connected

   • Open Outlook.
   • Look at the bottom-right status bar. If it says Disconnected, Working Offline, or Trying to connect, sync will fail.
   • In Outlook, open the Send/Receive tab and make sure Work Offline is not enabled.
   • Test your internet connection by opening a website in your browser.

2. Force Outlook to update the calendar

   • In Outlook, press F9 to run Send/Receive All Folders.
   • Switch to Calendar view and check whether recent events appear.
   • If you use a shared calendar, close it and reopen it:
     1. Right-click the calendar name.
     2. Select Delete Calendar or Close Calendar if available.
     3. Re-add it from Home > Add Calendar.

3. Restart Outlook and Windows

   • Close Outlook completely.
   • Open Task Manager with Ctrl+Shift+Esc.
   • In the Processes tab, end any stuck Outlook.exe process.
   • Restart your PC, then open Outlook again and check syncing.

4. Update Outlook and Windows

   • In Outlook, go to File > Office Account > Update Options > Update Now.
   • Then update Windows:
     1. Press Windows + I to open Settings.
     2. Go to Windows Update.
     3. Click Check for updates and install anything pending.
   • Restart your PC after updates finish.

5. Clear possible add-in conflicts

   • Press Windows + R, type outlook.exe /safe, then press Enter.
   • If calendar sync works in Safe Mode, an add-in is likely causing the problem.
   • Disable add-ins:
     1. In Outlook, go to File > Options > Add-ins.
     2. At the bottom, next to Manage COM Add-ins, click Go.
     3. Uncheck add-ins, click OK, and restart Outlook normally.

6. Repair the Outlook account

   • In Outlook, go to File > Account Settings > Account Settings.
   • Select your email account and click Repair if the option appears.
   • Follow the prompts, then restart Outlook.
   • If repair does not help, remove and re-add the account carefully.

7. Create a new Outlook profile

   • Close Outlook.
   • Press Windows + R, type control, and press Enter.
   • In Control Panel, search for Mail and open Mail (Microsoft Outlook).
   • Click Show Profiles > Add.
   • Create a new profile, add your account, then choose Always use this profile or test with Prompt for a profile to be used.
   • Open Outlook with the new profile and check the calendar.

Fix It Automatically with Kudu

If you do not want to dig through Outlook profiles, account settings, cache issues, and Windows sync problems by hand, Kudu can check the system for common causes automatically. It helps identify broken app settings, stale cache data, and other PC issues that can interfere with Outlook syncing, then applies fixes quickly.

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