iCal not refreshing after software update

Please try the following...

1. First check that all your settings are correct, that calendar syncing is checked on all devices (system preferences > iCloud on a mac and settings > iCloud on a iPhone, iPad or iPod).
2. If you are sure that everything is set up correctly and your calendars are in the iCloud account, you might try unchecking calendar syncing in the iCloud settings, restarting your device and then re-enabling calendar syncing settings.

Does it say anything when you click or hover on the exclamation mark in the triangle.

I'm not sure what else to suggest, it seems to be having problems connecting to the internet, but I assume since you are typing here you don't have a problem connecting to the internet.

No but you can nuke your iCloud settings rather than just signing in and out if you want to try.

1. Sign out of your account

(If you are unable to do this because System Preferences has frozen, Force Quit System Preferences and try again)

2. When prompted, opt to delete, contacts, calendars etc from your Mac.

(You are only deleting this data from your Mac, not from iCloud, the data will be reinstated when you log back in. If you need to check that the data is in iCloud before deleting it go to iCloud.com and check each section for data)

3. Having logged out, check that the iCloud accounts along with their data have disappeared from the Mail, Address Book and iCal Applications.

(If necessary, delete the iCloud accounts from each of these application separately from each Applications Preferences)

4. At this point it may be worth trying to log into iCloud from the System Preferences iCloud settings again, if this works, all well and good, if it doesn't continue to step 5.

5. Open your User Library folder in the Finder. (When in the Finder, go to the Go menu, hold down the option key (alt) and choose Library when it appears in the Go menu)

6. Navigate to Library > Application Support > iCloud and drag the iCloud folder to your desktop. (This action only copies the folder and will provide you with a back up)

7. Select the iCloud folder again in Library > Application Support and drag it to the trash, enter your administrators password when prompted.

8. Restart your computer.

9. You should now be able to enter your ID and Password in system Preferences > iCloud and log into your account. Check the services you wish to use and once you are satisfied it's working as it should, trash the iCloud folder you copied to your desktop earlier.

That's ok if you don't want to do that, it's up to you, but please remember...

(You are only deleting this data from your Mac, not from iCloud, the data will be reinstated when you log back in. If you need to check that the data is in iCloud before deleting it go to iCloud.com and check each section for data)

If you ctrl-click on the calendar do you see an "unsubscribe" option.

😎😁