What do you mean by "vsc app extension"?
What do you mean by "sdn"?
Since you posted under the Visual Studio.NET sub forum, I'm going to assume that you are trying to install Visual Studio 2022 otherwise also known as "VS2022".
Are you trying to install Visual Studio Code? Is that what you meant by the "vsc" part of "vsc app extension"? If so, Visual Studio Code is not an application extension. It is a stand alone application. It also more commonly referred to as "VS Code", not as VSC. VS Code allows extensions to be installed.
Is tis server that you are installing on your own personal server, or is owned by the company you work for? Is the server on your personal network, or is it on the company network? A lot of companies apply restrictions to servers so that only certain software can be installed, as well as, network connections are restricted. As part of the VS2022 installation, it downloads other components. If those downloads are blocked, you could see the installer freezing, and then eventually timing out.
Also, in general, it's a bad idea to do development directly on the server. You should do development on your workstation, and then deploy to the server.
