Q: Suddenly icloud calendar will not load on my Lenovo PC.  Has worked for months;  icloud contacts and pictures both continue to work.  Any suggestions?

Hi scschwind,

I understand that you are experiencing some issues with your iCloud calendar on your Windows computer. Here is an article for you that will help you address this issue:

Microsoft Windows (Microsoft Outlook)

After each step, check to see if the issue still exists. 

Check the system requirements

Make sure that your PC meets the iCloud system requirements.

Check your Internet connection

1. Try to go to www.apple.com. If you can’t connect to the Internet, your iCloud calendars and events won’t update in Outlook. Get help with your Internet connection.
2. Try to open a secure website from your PC to see if you can access ports 80 and 443. If the website doesn't open, you don't have access. Contact your Internet service provider for help. Safari requires access to port 443 to push updates between iCloud and your devices.

Check your settings

Open iCloud for Windows and make sure that you're signed in to the same iCloud account that you're using on your other supported devices.

Refresh Outlook

If you recently made changes in Outlook that aren't updating on your other devices (or the other way around), click the Refresh button in Outlook.

Turn off iCloud Calendar and turn it back on

1. Close Outlook.
2. Open iCloud for Windows.
3. Deselect the Mail, Contacts, Calendars & Tasks checkbox and click Apply.
4. Wait a few seconds. Select Mail, Contacts, Calendars & Tasks, and click Apply.
5. Open Outlook.

Make sure the iCloud Outlook Add-in is active within Outlook

In Outlook 2010 and later:

1. Click the File menu.
2. Click Options in the left panel.
3. Click Add-Ins in the left panel of the Outlook Options window.
4. Look at the list of add-ins in the Active Application Add-Ins section.
5. Select the iCloud Outlook Add-in.

In Outlook 2007:

1. From the Tools menu, select Trust Center.
2. Select Add-ins from the left column.
3. Look at the list of add-ins in the Active Application Add-Ins section.
4. Select the iCloud Outlook Add-in.

Make sure iCloud isn’t your default account in Outlook

• In Outlook 2010 and later, select File > Info > Account Settings > Data Files. If iCloud is listed as the default account in the Comments column, select a different account and click Set as Default.
• In Outlook 2007, select File > Data File Management > Data Files. If iCloud is listed as the default account in the Comments column, select a different account and click Set as Default.

Restart your computer

After you restart your computer, see if you fixed the issue.

Find your calendars in Microsoft Outlook

Learn how to manage Add-ins with Microsoft Outlook.

1. Make sure Calendar is turned on in iCloud for Windows.
2. Look for your data in the iCloud folder within Outlook. You can also view your data in Deleted Items in your Outlook Folder List.

If you find your calendar data in the Deleted Items folder, it isn’t because iCloud removed your data. When you turn on Mail, Contacts, Calendars & Tasks in iCloud for Windows, iCloud copies your calendar data from the default Outlook .pst file to iCloud. Then iCloud removes the calendar data from the .pst file by placing it in the Deleted Items folder in Outlook. The calendar data then moves to the iCloud data set within Outlook, so that iCloud can push the data to and from Outlook.

Get help using iCloud Calendar - Apple Support

https://support.apple.com/en-us/HT203521

Thanks for using the Apple Support Communities!

Hey again scschwind,

Thank you for using the Apple Support Community. Due to the nature of your issue or question you may find more information by using another one of Apple's support resources - https://getsupport.apple.com/.