1. Check the network connection: Make sure your device is connected to a stable network. Sometimes, the unstable network connection may cause the problem that you can't log in or load the bill.

2. Check the system requirements: make sure your equipment meets the requirements of the sign-in system of Zhongnan Hospital of Wuhan University. You may need a specific operating system, browser or other software to check in properly.

3. Clear the cache and cookies: clear the browser's cache and cookies, and then reload the check-in page. There is a problem with the browser's cache and cookies, which may cause the bill to be loaded incorrectly or checked in incorrectly.