A "403 Forbidden" error in WordPress is typically an indication that the server understands the request, but refuses to authorize it. This can be caused by various factors. Here are steps to diagnose and resolve the issue:

1. Check File and Directory Permissions:

   • Incorrect file or directory permissions can lead to a 403 error. Make sure that your files and directories have the correct permissions. Typically, directories should have a permission of 755, and files should have 644.

2. .htaccess File:

   • Incorrect rules in your .htaccess file can cause a 403 error. Try renaming or temporarily removing the .htaccess file to see if that resolves the issue.

3. Check for IP Restrictions:

   • If you have security plugins or server configurations in place, they may be blocking certain IP addresses. Make sure that your IP is not blocked.

4. Review Security Plugins or Firewall Settings:

   • If you're using a security plugin or a firewall, it might be blocking access. Check the settings of your security plugin or firewall to ensure that your IP is not blocked.

5. Check Directory Indexing:

   • If directory indexing is disabled on your server, make sure you have an index.php or index.html file in your directory. Without it, the server may return a 403 error.

6. Disable Hotlink Protection:

   • If you have hotlink protection enabled on your server, it may be blocking certain requests. Check your server settings or hosting control panel to disable hotlink protection.

7. Clear Browser Cache and Cookies:

   • Sometimes, a cached page might be causing the issue. Clear your browser cache and cookies, and try accessing the page again.

8. Check for URL Typos:

   • Make sure you're entering the correct URL. Typos in the URL can lead to a 403 error.

9. Review Plugin and Theme Conflicts:

   • Deactivate all your plugins and switch to a default theme. If the error goes away, reactivate each plugin one by one to identify the conflicting one.

10. Contact Hosting Support:

    • If none of the above steps work, contact your hosting provider's support team. They can review server logs and configurations to identify and resolve the issue.

11. Inspect Server Logs:

    • Review your server's error logs for any specific information about the 403 error. This can provide more context on what's causing the issue.

Remember to always back up your site before making significant changes to files or settings. This allows you to revert back if any further issues arise.