Hi there! I understand how frustrating it can be to encounter a blank white screen when trying to use HCMToGo on your phone. Let’s work through this together.

First, could you let me know which device and operating system you’re using? Knowing that will help me guide you with the right steps. If you're using a specific version of the app, that would be helpful too!

Here are a few initial troubleshooting steps you can try:

1. Refresh the App: Sometimes, simply closing the app completely and reopening it can solve the issue. Make sure to swipe it away from your recent apps list.

2. Check Internet Connection: Ensure that your phone is connected to the internet. You might want to switch between Wi-Fi and mobile data to see if that makes a difference.

3. Clear Cache (if on Android):
- Go to your phone's Settings.
- Tap on Apps or Applications.
- Find and select HCMToGo.
- Tap on Storage and then Clear Cache.

4. Reinstall the App: If the above steps don't work, uninstalling and reinstalling the app can often resolve persistent issues:
- Go to your phone's Settings > Apps > HCMToGo.
- Tap on Uninstall.
- After that, reinstall the app from the app store.

Give these steps a try, and let me know if the issue persists!