How do I fix 'cannot verify server identity' for Google Calendar on Mac?

Wirbr wrote:

The message cannot verify server identity of “calendar.google.com” keeps popping up even when I am not using the calendar app. I do not want to delete any of the registered calendars without erasing everything. Whenever I click on details it doesn’t give me a way to get rid of the problem. The message pops up about every two minutes.

https://discussions.apple.com/content/attachment/27bc34d4-0c91-490e-96f1-e2ce40d0e6b6

[Edited by Moderator]

The "cannot verify server identity" error with Google Calendar often indicates an issue with the SSL/TLS certificate used by the server. This can be due to a variety of reasons, including outdated software, incorrect date/time settings, or even corrupted cache. Here's how to troubleshoot it: 

1. Check for Outdated Software or Operating System:

• Ensure your device's operating system and any relevant software (e.g., calendar app) are up to date. Outdated versions may have compatibility issues with the latest security protocols. 

2. Verify Date and Time Settings:

• Make sure your device's date and time are accurate. Incorrect date and time settings can cause issues with verifying server identities. 

3. Clear Cache and Cookies:

• Clear the browser's cache and cookies. This can resolve temporary issues with the server's identity. 

4. Check for Subscribed Calendars:

• If you have subscribed to other calendars, try removing them and see if the issue persists. 

5. Reset Network Settings:

• Resetting your network settings can sometimes resolve connection-related problems.

6. Contact Support:

• If the problem persists, contact Google Calendar support for further assistance.

Troubleshooting for Specific Devices:

• iOS/iPadOS:
• If using the iOS Mail app, verify incoming and outgoing server settings in Settings > Mail > Accounts.
• Android:
• Refer to the Calendar app settings or the device's system settings for network and connection-related troubleshooting. 

Note: The specific steps may vary depending on your device and the application you are using (e.g., Google Calendar, a third-party calendar app).