Calendar subscribe/refresh fails with Error 4 on macOS Ventura

I got this same error message! I'm using macOS Ventura 13.3 on my MacBook Pro and my Calendar app (Version 11.0 (2932.4.5)) won't sync one particular Google calendar that I'm subscribed to. It will sync the other Google calendar that I'm subscribed to, though.

It's weird because my iPad Pro (iPadOS version 16.4) and iPhone 12 (iOS version 16.4) sync both Google calendars that I'm subscribed to just fine. What makes this even weirder is that I'll get the message that you posted every time I try to manually refresh my Calendar app on MacBook Pro, but if I leave it alone for a few hours the Calendar app will actually sync like it's supposed to. Then, if there's a change on the Google calendar and I want to manually refresh the Calendar app, the message will pop up again. It doesn't make sense.

In summary:

• My Calendar app on macOS Ventura struggles to sync one Google calendar that I'm subscribed to
• The Google calendar will eventually sync on my laptop after a few hours, but the error message remains if I try to manually refresh the calendar subscription
• My iPhone and iPad sync that same calendar just fine whether or not I manually refresh it.

I don't have a solution for this, but I'm hoping that adding my details helps others figure out what's wrong.

Hello pintux,

To start off, we advise that you restart your Mac (Shut down or restart your Mac). Once that is done, please test this issue.

If the issue persists, continue by testing to see when this behavior occurs. First, put your Mac into safe mode and test. Booting into safe mode will disable any startup and login items from automatically opening, which can help us to isolate the source of the issue further. When you do this, you’ll see some unusual behavior from the display; this is to be expected. Please follow the steps in this article: How to use safe mode on your Mac. 

Next, let's see if this behavior persists in a new user account on your Mac. Testing in a new user will determine if you have a system-wide issue or if it's user-specific. Please follow these steps to make a test account that can be deleted later: Change Users & Groups settings on Mac. Once the new user account has been set up, log out of your own account then into the new one to test the issue.

Let us know how this goes, please. Thanks and take care.