When checking whether the resolution of the domain name A record is correct, you can go to the domain name management background to check whether the currently specified ip conforms to the ip of the server space. If it is wrong, click "Modify" to solve it correctly;
The second reason is to go to the server, check iis settings, and check whether the website is running normally. Click start-administrative tools-server Internet Information Server (IIS) manager in the lower left corner of the server.
Open the "Internet Information server (IIS) Manager" on our server and find that the website is in a "stopped" state, and then right-click "Start (S)" to solve it correctly;
The third reason is that the path pointed by the website is incorrect or does not exist. For example, the input folder was accidentally deleted and needs to be restored by website management.
The fourth reason is that the specified web page does not exist. For example, if the index.html in Figure 6 is deleted or tampered with, there will be http/IIS error request, 400 error and wrong request format.
400 means that 400 is a kind of HTTP status code and 400 is a bad request. Is the status code that the browser returns to the client when it opens a web page. A 400 page means that when a user opens a web page, it will return to the user interface with 400 prompts. It means that the domain name of the page you visited does not exist or the request is wrong. There are two main forms: 1, and a bad request means "wrong request"; 2. Invalid host name means "nonexistent domain name". Usually, this will only appear on Windows hosts. If it is a Linux host, different error prompts will be displayed. The reason for this error is that an additional domain arrived at a host, but the host did not bind a domain name, so IIS returned this prompt message. What should I do if I encounter this problem? The first solution is to Ping the domain name to see if it is resolved to the IP where the space is located. If so, go to the space management panel to see if your domain name is bound. If so, it must be the problem of the space provider. To solve this problem, we can only find a space provider to bind the domain name. If you have this right, you can bind the domain name yourself to solve the problem.