TypeError: Cannot read properties of undefined (reading ‘isPrimary’)

Hello,

We apologize for the issue you are facing with the error message. This TypeError often indicates a JavaScript conflict, which can occur due to other plugins or themes installed on your website.

To troubleshoot this issue, we recommend the following steps:

1. Open the Developer Tools Console Panel: You can do this in Chrome by navigating to More Tools → Developer Tools and then clicking on the Console tab. Alternatively, you can use the keyboard shortcut Ctrl + Shift + J (Windows) or Cmd + Option + J (Mac).
   

2. Identify the Error: Check if there are any additional errors in the console that might provide more context about the issue.
   

3. Check for Plugin or Theme Conflicts: Disable other plugins one by one to see if the error persists. If it resolves after disabling a specific plugin, that plugin may be causing a conflict with Rank Math.

4. Firewall Settings: If you are using a firewall, ensure that it is not blocking any Rank Math files. You may need to whitelist Rank Math and its files.

If these steps do not resolve the issue, please reply to this ticket with any additional error details you find, and a human agent from the Rank Math Support team will assist you further.

Sources:
Why Your SEO Title, Description & Focus Keyword Aren’t Being Saved » Rank Math