The error message "No selector dir for user XXX" in the context of a PHP Selector typically means that the PHP Selector is unable to find the directory where user-specific PHP versions and configurations are stored.

Here are steps you can take to troubleshoot and potentially resolve this issue:

1. Check if PHP Selector is Installed: First, ensure that PHP Selector is installed on your server. If it's not installed or configured properly, it won't be able to manage user-specific PHP versions.

2. Verify User: Make sure that the user mentioned in the error message (XXX) exists on your system.

3. Verify PHP Selector Configuration: Double-check the configuration of your PHP Selector. Ensure that it's set up correctly to manage PHP versions for individual users.

4. Check Permissions: The PHP Selector directory and related files must have appropriate permissions for the user to access them. Ensure that the directory structure and files are accessible and have the correct ownership and permissions.

5. Reconfigure PHP Selector: Try reconfiguring PHP Selector. This might involve reinstalling or reconfiguring the PHP Selector tool to ensure it's properly set up.

6. Check PHP Versions: Verify that the PHP versions you're trying to select are installed on the server and available for PHP Selector to manage.

7. Contact Hosting Provider or System Administrator: If you're using a web hosting service, it's possible that they have specific configurations in place or limitations on the usage of PHP Selector. Contact your hosting provider or system administrator for further assistance.

8. Review Documentation or Support Resources: Check the documentation or support resources provided by your hosting provider or the PHP Selector tool's developer. They may have specific troubleshooting steps or recommendations.

9. Review Logs: Check server logs for any specific error messages related to PHP Selector. These logs can provide more detailed information about what might be causing the issue.

Remember, the exact steps to resolve this issue can vary depending on your server environment, the specific PHP Selector tool you're using, and any custom configurations in place. If you're unsure about any of these steps, it's a good idea to consult with your hosting provider or system administrator for tailored assistance.