It may be a system update problem. You can uninstall the original library and reinstall the login.

Open the Superstar Mobile Library client and click on the avatar.

At this time, it will show that you have not logged in, and then click on the avatar.

Then you will automatically locate the list of nearby libraries, choose your own library, enter the account number and password of your library card, and click Login.

Then you will jump to the interface, showing that you have logged in successfully.