Experiencing a white screen when using MileagePlus X can be a nuisance, but there are several steps you can take to troubleshoot and resolve this issue. Follow these actionable steps:

1. Clear Browser Cache and Cookies:
- Open your web browser settings.
- Navigate to the privacy or history section.
- Choose the option to clear browsing data, ensuring you select cookies and cached files.
- Restart the browser and check if the issue persists.

2. Try a Different Browser:
- Download and install an alternative web browser (e.g., Chrome, Firefox).
- Open MileagePlus X in the new browser to see if the problem continues.

3. Disable Browser Extensions:
- Go to your browser's extension settings and disable all extensions.
- Restart the browser and access MileagePlus X again. If it works, enable extensions one by one to identify the culprit.

4. Check for Software Updates:
- Ensure your operating system and web browser are fully up to date.
- Look for updates in the system settings for Windows and check your browser for updates as well.

5. Review Your Internet Connection:
- Make sure you have a stable internet connection.
- Try resetting your router or switching to a different network.

6. Log In Using the App:
- If the issue persists on the web, check if you can access MileagePlus X using the mobile app. Sometimes, the app functions better than the website.

7. Look for Known Issues:
- Check forums and community discussions such as the United Airlines subreddit or FlyerTalk forums to see if other users experience similar issues. For instance, some users have reported a white screen after signing into the MileagePlus account, which could suggest server-side issues - learn more - learn more.

8. Contact Customer Support:
- If the above steps do not resolve the issue, consider reaching out to United Airlines customer support. They may provide specific fixes based on the current system status or known outages.

9. Reinstall the App:
- If you are using the MileagePlus X mobile app, try uninstalling and then reinstalling it. This can help reset any corrupted data that is causing the issue.

Following these steps should help you address the white screen problem with MileagePlus X. If issues continue, keep an eye on updates from United Airlines as they may be implementing fixes for ongoing problems.