The error message you provided, this.appRef.components[0] is undefined, suggests a JavaScript error related to the CloudLinux Manager interface. This type of error typically occurs due to a problem with the web application's front-end code.

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

1. Clear Browser Cache:

   Sometimes, cached files can cause conflicts or errors. Try clearing your browser cache and cookies, then attempt to log in again.

2. Try a Different Browser:

   Test accessing CloudLinux Manager using a different web browser to see if the issue persists. This can help determine if the problem is specific to one browser.

3. Check for Updates:

   Ensure that your browser is up-to-date. An outdated browser may not be fully compatible with the web application.

4. Check for System Updates:

   Make sure your operating system and any related software are up-to-date. Sometimes, outdated system components can lead to compatibility issues.

5. Contact Support:

   If none of the above steps work, consider reaching out to CloudLinux support or the support forum/community associated with CloudLinux Manager. They may have encountered this issue before and can provide specific guidance.

6. Inspect Console for Additional Errors:

   Open the browser's developer console (usually by pressing F12 or right-clicking and selecting "Inspect" then navigating to the "Console" tab). Look for any additional error messages that might provide more context about the issue.

7. Check for Known Issues or Release Notes:

   Consult CloudLinux's release notes, forums, or knowledge base for any known issues related to logging in as a reseller. There might be a documented solution or workaround.

8. Browser Extensions/Plugins:

   Certain browser extensions or plugins can sometimes interfere with web applications. Try disabling any extensions that might be affecting the CloudLinux Manager interface.

9. Verify Network Connectivity:

   Ensure that there are no network issues that might be causing the web page to load improperly.

10. Check for JavaScript Errors:

    If you have access to the source code of the page, you can inspect it for potential JavaScript errors. Look for issues related to this.appRef.components.

Remember to provide detailed information when seeking help from support or forums, such as the specific steps you took, any error messages, and your system/browser details. This will help others diagnose the issue more effectively.