The reason for this is that IIS of the library management system is set as the default application. In other words, this system was first successful on another person's computer. She has configured IIS and even created a connection. However, when it comes to you, using someone else's system becomes a configuration problem!

Main solutions:

1. You can reconfigure IIS and set its virtual directory to the address that the system points to.

2. Rebuild a website by yourself and load files from the original website. Remember, the Web.config file cannot be loaded.