Install mono-fastcgi-server4 by entering the following commands in the terminal:
sudo apt update sudo apt install mono-fastcgi-server4
Description:
ASP.NET 4.0 backend for FastCGI webservers
mono-fastcgi-server contains the backend for FastCGI. It lets you run ASP.NET web applications via HTTP servers such as Lighttpd or Apache. The FastCGI webserver shouldbe configured to run fastcgi-mono-server to parse and compile the aspx code. . This package requires you to install any FastCGI webserver, such as Lighttpd or Apache (see libapache2-mod-fcgid).
Homepage: http://www.mono-project.com/ASP.NET
Version: 4.2-2.1
Section: universe/web